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About this book

This book comprises select peer-reviewed proceedings of the 26th National Conference on IC Engines and Combustion (NCICEC) 2019 which was organised by the Department of Mechanical Engineering, National Institute of Technology Kurukshetra under the aegis of The Combustion Institute-Indian Section (CIIS). The book covers latest research and developments in the areas of combustion and propulsion, exhaust emissions, gas turbines, hybrid vehicles, IC engines, and alternative fuels. The contents include theoretical and numerical tools applied to a wide range of combustion problems, and also discusses their applications. This book can be a good reference for engineers, educators and researchers working in the area of IC engines and combustion.

Table of Contents


Plenary Invited Contributions


Impact of Flowfield on Pollutants’ Emission from a Swirl-Assisted Distributed Combustor

Colorless distributed combustion (CDC) is a novel method to enhance flame stability and thermal field uniformity, increase combustion efficiency, and reduce pollutants’ emission. CDC is achieved through the use of a carefully prepared fuel–oxidizer mixture along with reactive species. In this study, a partially premixed, swirl-assisted cylindrical combustor utilized a propane–air flame with either nitrogen or carbon dioxide gas in order to reduce the oxygen concentration of the oxidizer. OH* chemiluminescence signatures were used to determine transition to distributed combustion condition. The results showed transition to CDC at approximately 15% using N2 and 17% using CO2 dilution. Emission of NO and CO under CDC condition showed NO levels of only 2 or 1 ppm using N2 or CO2 dilution, respectively. High-frequency PIV (3 kHz) was used to determine the flow velocity structure and eddy size effects on flame stability and emissions. Increase in dilution enhanced both the radial and axial mean and fluctuating velocities under CDC that foster mixing. Additionally, the Kolmogorov length decreased with increase in dilution resulting in smaller eddy size particularly in the swirl lobe region, which enhanced turbulent dissipation that resulted in lower peak temperatures and reduced thermal NOx emission. Reduced viscosity using CO2 dilution provided a stronger effect in reducing NO as compared to N2 as the diluent.

Joseph S. Feser, Serhat Karyeyen, Ashwani K. Gupta

Emerging Engine Technologies for Reducing Fuel Consumption and Emissions

Two major societal problems that we, combustion scientists and engineers, can address are as follows: (a) How to deal with the depletion of worldwide petroleum-based fuel resources? and (b) how to reduce the harmful emissions from burning these hydrocarbon fuels? Of course, the answers to these questions are complex and involve both technical and non-technical entities throughout the world.

K. Kailasanath

Synopsis of Propulsion Engine Combustion Technology/Product Development and Analysis Substantiated During Last 47 Years

An overview is given of hypothesis-based combustion technology and product design and development practiced since the early 1970s applied successfully for 36 combustion systems including description of author’s six most favorite advanced combustion schematics. The challenges of developing the three technologies and products, low emission combustors (LECs), dual-annular combustors (DACs) and TAPS at GE Aviation and CFM, and the lessons learned to further continue making continuing progress have been summarized. While the landing takeoff NOx of the third-generation single venturi lean direct injection demonstrated in an idealized multi-injector test rig shows potentials for achieving 50% reduction compared to current lowest NOx GEnx TAPS combustor, its future activities should be focused on reducing low-power CO and HC emissions in addition to commonly encountered operability challenges associated with lean-dome combustors.

Hukam C. Mongia

Emission Characteristics on Combustion of HEFA Alternative-Aviation Fuel Under In-Flight Conditions

Global climate change, due to the rapid increase in CO2 emissions, especially caused by aviation, is one of the critical issues to be solved through international collaborations.

Hitoshi Fujiwara, Keiichi Okai

What Artificial Intelligence Can Do for You

In the course of the last two decades, artificial intelligence progressively spread into many areas of research and development, even to those where it was far from being expected and that was always regarded as self-sustainable and as kinds of closed universes (e.g., mechanical engineering or, let us say, Egyptology). This talk discusses several ways artificial intelligence techniques can be deployed in the area of combustion (or more generally chemical process modelling) and what benefits could be expected from doing so. Naturally, the disadvantages of artificial intelligence techniques are discussed as well.

Kamil Ekštein

Experimental Investigation of Aromatic Blended Binary Fuel on Pollutant Emissions from Compression Ignition Engine

Direct injection diesel-fueled engines have been extensively used for automotive applications due to their higher thermal efficiency and lower carbon dioxide emissions. However, high particulate matter (PM) and NOx emissions from these engines are still an issue that needs to be addressed. The modification of fuel components like structure, contents, and properties are expected to be the crucial countermeasures to improve the overall performance of the fuel in the engine. Aromatics are the essential component of the fossil-based diesel fuel to provide the lubricity to engine parts lubricated by fuel itself. However, aromatics have a higher tendency to promote the PM formation from diesel engines. Therefore, the study of the aromatics content in the fuel and its structure has great significance in engine applications. In the present study, three different aromatics were used to investigate their impact on diesel engine characteristics. Aromatics were blended with de-aromatized higher chain alkanes as binary fuel blends. Higher aromatics blending in binary mixture led to higher PM emissions. Due to a higher degree of unsaturation, polycyclic single and double-ring aromatics (indene and methylnaphthalene) produce higher pollutant emissions as compared to single-ring monocyclic aromatics (toluene).

Paramvir Singh, Saurabh Sharma, Bandar Awadh Almohammadi, Sudarshan Kumar, Bhupendra Khandelwal

Fuel Development and Alternative Fuels


Experimental Investigation on a Compression Ignition Engine with Blends of Plastic Oil and Diesel as Fuel

Waste plastic is a conventional source of energy. It can be transformed into oil by thermal degradation method such as pyrolysis. In this work, pyrolysis plastic oil (PPO) was prepared by microwave pyrolysis method using waste plastic. The plastic oil was analysed, tested and used as the properties of it were similar to that of diesel. The single cylinder direct injection diesel engine was fuelled with different blends at different loads from no load to full load condition. The performance, combustion characteristics and emissions were recorded and compared with that of diesel. Based on the results, it is found that the brake thermal efficiency for blends PPO20, PPO40, PPO60, PPO80 and PPO100 at 90% of full load condition were lower by 3.9, 6.8, 8.3, 9 and 9.7%, respectively, with respect to diesel when the engine was operated at a constant speed of 1500 rpm. Specific fuel consumption for blends PPO20, PPO40, PPO60, PPO80 and PPO100 at 90% of full load were higher by 0.4, 1.2, 2, 3.6 and 6%, respectively, as compared to diesel at constant speed (1500 rpm). The NOx emissions for blends PPO20, PPO40, PPO60, PPO80 and PPO100 at 90% of full load were higher by 7.65, 13, 17, 23 and 24.2%, respectively, as compared to diesel while engine was running in constant speed (1500 rpm). The CO emissions for PPO blends PPO20, PPO40, PPO60, PPO80 and PPO100 at 90% of full load were lower by 6.5, 17.4, 26, 30.4 and 7.6%, respectively, as compared to diesel at constant speed (1500 rpm). The UHC emissions for PPO blends PPO20, PPO40, PPO60, PPO80 and PPO100 at 90% of full load were lower by 6.5, 17.4, 26, 30 and 39%, respectively, as compared to diesel at constant speed (1500 rpm). It can be concluded that the plastic oil could be used as a substitute fuel in diesel engine.

Manoj Kumar, J. M. Mallikarjuna

Combustion Characteristics of Conventional Diesel Engine and Low Heat Rejection Diesel Engine with Biodiesel Blends

The combustion properties such as ignition delay, duration of combustion phases, and rate of pressure rise are important to optimize performance and emission level of diesel engine. Thermo-physical characteristics of diesel and biofuels are different and hence their final outcomes are also different. The objective of the work is to determine combustion characteristics of jatropha biodiesel blends and compare with baseline diesel in conventional engine (CE) as well as low heat rejection engine (LHRE). 10% biodiesel in 90% diesel called B10 and 5% ethanol, 10% biodiesel, and 85% diesel called E05B10 by v/v ratio are used as biodiesel blends. Crown surfaces of piston, cylinder head, and both valves are insulated with 250 µm thick mullite thermal barrier coating material to form LHRE. The ignition delay of baseline diesel with CE is 7.35 °CA at maximum engine load operation. For biodiesel blends B10 and E05B10, it reduces by 0.21 °CA and 0.09 °CA, respectively, in CE operation. It further reduces by 0.27 and 0.11 °CA for B10 and E05B10, respectively, during LHRE operation. Premixed combustion with baseline diesel in CE is 10.54 °CA. For biodiesel blends B10 and E05B10, it is increased by 0.94 and 0.30 °CA, respectively, during CE operation. It is further increased by 1.30 and 0.48 °CA for B10 and E05B10, respectively, during LHRE operation. Thus, the effects on combustion characteristics with biodiesel blend and by adding small amount of ethanol in biodiesel blend are evaluated in both CE as well as LHRE.

Sharad P. Jagtap, Anand N. Pawar, Subhash Lahane, D. B. Lata

Performance and Emission Analysis of RCCI Engine Fuelled with Acetylene Gas

The consistent demand for the diesel fueled vehicles is expanding quickly. Because of consumption of conventional fuels, the world needs to discover alternative fuel to run the diesel vehicles. The alternative fuel innovation should give more effectiveness in engine performance and emanate negligible measure of pollutants like CO, HC, NOx, and particulate matters. The emerging method which is named as reactivity-controlled compression ignition (RCCI) demonstrated higher thermal efficiency and lower emission. In this investigation, as per the RCCI technique, the low reactivity fuel acetylene is introduced at different flow rates into manifold. At that point, the high reactivity diesel is acquainted in a conventional manner to combustion chamber. The outcome demonstrates the impressive improvement in the performance characteristics, and also environmental pollutants like smoke, CO, and HC emissions are diminished. The NOx emissions are somewhat increased when compared with the diesel fuelled operation.

M. Sonachalam, V. Manieniyan

Engine Performance and Emission Studies with Cotton Seed—Simarouba and Cotton Seed—Mahua Oil Blends as a Partial Replacement Biofuel

In the present paper, the performance of a single cylinder CI engine using dual blend of cotton seed—Simarouba oil (CSSB) and cotton seed—Mahua oil (CSMB) biodiesel was investigated. To accomplish this, CSSB and CSMB blends are used in equal proportions in diesel to prepare three different blend ratios B10 to B30 with an increment of 10%. Test run was done to evaluate different performance parameters at normal and advanced injection timing keeping compression ratio constant. Performance study revealed that the highest brake thermal efficiencies recorded by the respective blends CSSB30 and CSMB30 were 28.4% and 29.8% as against 29.1% of neat diesel with 4–8% more fuel consumption per kW of power generated, compared to neat diesel. Also considerable drop in emission was found in CO, UBHC at full load conditions, compared to diesel, respectively, between 25% less CO (at half load and with CSSB20) and 2.85% less UBHC (at half load and with CSSB10) to 71.42% less CO (at full load and with CSMB30) 57.69% less UBHC (at full load and with CSMB30), respectively. Advancing the injection, HC emission increased from 3.5% at ¾ load to 35.48% at full load (CSSB20 blend) compared to diesel. Further, it could be noted that CO emission with advanced injection was still lower (even though it increased by 50% compared to normal injection with CSSB20A) except at full load where diesel emitted 31.94% (compared to CSSB20) and 92.69% (compared to CSMB20) less. To conclude, the lower biodiesel blends of CSSB and CSMB could be used as partial replacement to diesel, with comparable engine performance coupled with lower UBHC and NOx emissions.

Ramakrishna N. Hegde, B. Jagadeesh

Effect of Bio-Additive Blends with Diesel Fuel Utilization in a Diesel Engine

Many countries are increasingly interested in finding appropriate alternative fuels that are environmentally friendly. While straight vegetable oils can be used in diesel engines, their elevated viscosities, low volatility, and bad cold flow properties have resulted in multiple derivatives being investigated. In the present work, bio-based additives were used, since they are nontoxic and have biodegradable properties. This work was carried out in two phases. In the first phase, a new bio-additive was prepared from the Mahua oil. The chemical properties of the blends were determined. In second phase, the biofuel additive (BFA) was blended with diesel in the ratios of 1.0 ml, 1.5 ml, 2.0 ml, 2.5 ml, 3.0 ml, and 4 ml for every 1 liter of diesel, the performance, emission, and combustion characteristics were determined. The 2.0 ml blend turned out to be the best BFA blend.

R. Senthilkumar, V. Sukumar, V. Manieniyan, S. Sivaprakasam

Experimental Investigation of the Influence of Nanoparticle Additive with Biodiesel in Diesel Engine

The innovation for utilization of biodiesels (up to 20%) as elective fuel in diesel engines has just been built up. In any case, there are a few weaknesses related to the utilization of biodiesels as it has high-level density, viscosity and heating value maximum fuel utilization and high-level NOx, which confines its application. Improving the performance and the decrease in emission by the application nanoparticles comprises one of the primary keys for safeguarding country’s economy and wellbeing. In such manner, nanoparticles become basic and pivotal instruments because of its elevated surface zone to quantity proportion of nanoparticle bringing about good atomization and quick dissipation of fuel advancing efficiency. In this test examination, biodiesel is obtained from chicken fat methyl ester by transesterification is heated up to 50 °C. Then, methanol is added to preheat CFO. After this reaction, the bottom deposit is detached from the reaction (base transesterification). The obtained mixture is heated for 45–55 min in the presence of potassium hydroxide (KOH) and methanol. In the current effort, the experimentation was conducted by diesel engine at a uniform speed of 1500 rpm by utilizing three distinctive concentrations of nickel oxide nanoparticles 50, 75 and 100 ppm are examined. The 100-ppm nickel oxide nanoparticles and its blends BTE were improved and compared to diesel. Lowered the CO, HC and NOx emissions

T. Deepak Kumar, Manjunatha, D. K. Ramesha

Performance, Emission and Combustion Characteristics of Turpentine Cottonseed Oil Ester Blend

In the current study, an experimental investigation was carried out with cottonseed oil ester and mineral turpentine oil blend as a alternative fuel in a diesel engine. High heating value turpentine oil with low firing point is blended with high cetane number cottonseed oil ester for better performance. In this study gives the comparative measures of brake specific fuel consumption. The performance, emission and combustion characteristics of the fuel blend are studied at various loads and compare with that of diesel. The experiment was conducted on a 5.2 kW single cylinder compression ignition engine. Fuel blends in various ratios have been tested. The turpentine oil was first blended with 20%, 30%, 40%, 50% of cottonseed oil ester and it was found that the blend T50 given the optimum brake thermal efficiency among all the blends. However, the CO2 and NOx emissions are lesser for T60 blend.

P. Udayakumar, G. Kasiraman

Experimental Catalyst Optimization and Artificial Neural Network Modeling in Biodiesel Preparation

Biodiesel preparation is broadly led through transesterification process with homogeneous or heterogeneous catalyst. The most remarkable catalyst utilized in preparing biodiesel is the homogeneous catalyst, for example, NaOH, KOH, Na2O2, and CH3ONa. The decision of selecting among these catalysts is because of their higher response rates. Accordingly, this paper examines the impacts of various catalyst utilized for preparing biodiesel. Machine learning has demonstrated to be an amazing for various modeling during the previous decades. Artificial neural networks (ANN) stand out among the most prominent modeling methods investigated. The utilization of ANN for improvement of catalyst in biodiesel preparation was not well‐studied until ongoing decades. In this analysis, the focus is on the use of ANNs for catalysis advancement in biodiesel preparation. From the points of view of experimental analysis and ANN modeling, this investigation indicates how ANNs can be adequately connected for catalyst optimization in biodiesel preparation.

P. Deivajothi, G. Vinodhini, V. Manieniyan

Performance Evaluation of Hydrogen-Fuelled Internal Combustion Engine

For development in alternate energy sources basket and the adverse effects of the emissions from the fossil fuels on environment and life forms, research towards developing alternate energy that can be used for both transportation and power generation has gained momentum. As the world advances towards the sustainable solutions, development of more environment-friendly fuel, and substituting it for the conventional fossil fuels, becomes the need of the hour. The hydrocarbon-based fuels, viz. petrol, diesel, etc., are being used as the major sources of energy since the past decades. They are being used for both power generation and transportation. Burning of these alternative fuels results in the emission of CO2 and other species which are harmful to the nature. Moreover, carbon dioxide, which is the major contributor to the greenhouse effect, is a big concern. From the alternate energy sources basket, hydrogen is the most versatile, the most eco-friendly and the most promising substitute for conventional fossil fuels. It is one of the most prominent alternatives for carbon-based fossil fuels. The main reasons behind hydrogen as the most sought fuel are its easy availability, less harmful (or no carbon) emissions and its high energy content. Several barriers have to be overcome before the marketization of hydrogen as a transport fuel for internal combustion engines. Apart from having uncountable advantages over fossil fuels, hydrogen as a fuel has limitations also such as backfire, moisture ingress in engine oil and high NOx emissions. However, the problem of backfire can be worked upon by developing better fuel injection technologies, and the problem of moisture ingress and high NOx emission can be studied and thus worked upon by running the engine performance test for 100 h as per IS 10,000 (part IV). Also, although theoretically combustion of hydrogen results only in the formation of water as a by-product, researches have revealed that on combustion of hydrogen in SI engine, a small amount of NOx, CO, PN, CO2 is also produced. These may be due to the engine oil. Thus, the following paper focuses on a series of experimental investigations performed on a commercial genset fuelled with pure hydrogen fuel and coupled with a four cylinders internal combustion engine. The experiments were performed to evaluate the durability of the dedicated lubricant developed for the H2-fuelled genset and to study the performance of the genset for 100 h under cyclic conditions along with periodic performance and emission tests at every 48 h.

Sauhard Singh, V. K. Bathla, Reji Mathai, K. A. Subramanian

Effects of Methanol Substitution on Performance and Emission in a LPG-Fueled SI Engine

The current rate of depletion of fossil fuels has created an imbalance in the energy exchange. Stricter emission standards are enforced in order to control the environmental pollution and global warming. Both these factors have led to a shift from usage of conventional fossil fuels to other alternative resources. LPG serves as a viable alternative option owing to its suitability to fuel SI engines and its obtainability from large scale shale gas reserves. Being a gas at atmospheric condition, it offers proper homogenization and is best suited for lean-burn conditions. Adding methanol in small amount to LPG lowers the combustion temperature due to the latent heat of vaporization and improves lean operation due to oxygen content contributing in reduction of NOx. This work is focused on NOx reduction as it is hazardous and main constituent in the formation of PM, smog and acid rains. An experimental study is conducted in a single cylinder diesel engine modified to operate as SI engine at an optimized compression ratio of 10.5:1 and 1500 rpm fueled by LPG. The effects of methanol substitution were investigated in reduction of NOx emissions at 100% throttle condition by injecting 10, 20 and 30% of methanol on energy basis into the intake port of engine. The results have been analyzed with Brake Effective Mean Pressure (BMEP) as it serves as an important yardstick to compare different criteria. The experiments were performed at BMEPs of 4, 4.5,5 and 5.5 bar. There is a significant improvement in brake thermal efficiency along with decrease in the NOx emission as the percentage of methanol in the fuel goes higher. The decrease in NOx is significant ranging from 83% at 4 bar BMEP to 12% at 5.5 bar. The lean operation was also improved on addition of methanol.

K. Ravi, E. Porpatham, Jim Alexander

Effect of Static Ignition Timing on the Emission and Performance Characteristics of a Four-Cylinder MPFI Engine Fueled by LPG

The present work aims on the experimental analysis of static ignition timing on MPFI gasoline engine with LPG as an alternative fuel. Four-cylinder MPFI engine setup is used with gasoline, 25% LPG, 50% LPG, 75% LPG, and 100% LPG fuel for different static ignition timing of 5, 8 and 11 deg. bTDC at full load and different speed conditions. The results have shown that 100% LPG is a better fuel on than other blends because of its lean combustion characteristics when compared with gasoline. Excluding NOx emission, 100% LPG shown better emission and performance characteristics at static ignition timing of 8 deg. bTDC. By advancing the static ignition timing, engine will work leaner side hence reduction in the fuel consumption and increase in the brake thermal efficiency are obtained. As the ignition timing is advanced, volumetric efficiency increases for all fuel conditions because of engine will work in leaner side. There is a positive effect on CO emission when static ignition timing advanced but slightly increased HC emission is obtained. But 100% LPG has shown lesser CO and HC emission when related to gasoline. Also, advancing the static ignition timing will result in higher NOx emission.

Vighnesha Nayak, K. S. Shankar, Anusha, P. M. Ashit, Bhushith, K. L. Vikyath

Optimization of Process Parameters of Paddy Straw Gasification System Using Taguchi Methodology

In this manuscript, optimization of input parameters associated with the gasification of paddy straw has been done by adopting a prominent optimization technique known as “Taguchi method”. An analysis of variance (ANOVA), orthogonal array is applied to discover the significant operating parameters effecting the generation of H2 & CH4 during paddy straw gasification process. Before implementation of Taguchi method, air flow velocity and equivalence ratio are selected as input parameters that influences the production of H2 & CH4. Results revealed that air flow velocity comes out to be significant input parameters in case of both H2 & CH4 generation rate.

Mohit Sharma, Rajneesh Kaushal

Investigation on Lean-Burn Spark-Ignition Engine with Methanol/Ethanol—Gasoline Blends

The aim of the current study was to know the performance and emission behavior of a modified single-cylinder lean-burn SI engine from a stationary diesel engine, runs with gasoline, binary and ternary mixtures of alcohol with gasoline. The tests were looked at 100% throttle open condition, at 10.5:1 compression ratio and fixed RPM of 1500 at different levels of intake charge through manifold injection. The results showed that ethanol-gasoline mixture (10% by volume 10%) was shown an improved performance characteristics compared with methanol-gasoline blend (by volume) and ternary blend of 5% of ethanol—5% methanol—(90%) gasoline blend (by volume) and also a noticeable extension in the lean operation with alcohol-gasoline mixtures. The exhaust emissions, HC and CO were reduced while CO2 and NOx emissions were increased owing to better combustion efficiency and high temperatures in the cylinder. Overall it is accomplished that low concentration of alcohol blending with gasoline enhances performance and reduces emissions under the lean operation of SI engine.

Suresh Devunuri, E. Porpatham, Zhen Wu

CFD Simulation Studies on Model Can-Type Combustor with Syngas and Enhanced Hydrogen Fuel Combustion

Syngas derived from coal or biomass becomes major source of energy for present and near-future power generation. The conventional fossil fuel-fired gas turbine combustors need attention to adopt variation in fuel. A model can-type combustor is considered in this study. Numerical simulations are carried out to identify the flow features in the combustor for a typical syngas combustion and artificially added H2 fuel combustion. Generally, syngas consists of CO and H2 combination in such a way that the mass fraction of CO is higher to reduce the influence of H2. The flow field generated by the syngas combustor has shown little variation in various quantities as compared with methane fuel. However, when increasing H2 content in the fuel, the streamline pattern changes. The flow field of enhanced H2 fuel combustion provided better upstream recirculation zone and higher values of temperatures. The fuel flow rate is varied in syngas and hydrogen-enhanced cases. It is noticed that the upstream recirculation is significant when there is intense heat release.

R. Ramkumar, Manoj Mannari, A. T. Sriram

Experimental Investigation on Performance and Emission Characteristics of Lime Treated and Preheated Biogas

This paper depicts the performance and emission characteristics of raw and lime treated–preheated biogas injected in conventional diesel engine operated at various compression ratios of 17, 17.5, 18 and 18.5. In this work, it was noted that the engine performance and emission characteristics can be greatly enhanced by treating the raw biogas with lime, providing a change in its characteristics which can be further changed by preheating. The obtained results show that lime treated–preheated biogas with compression ratio of 18 provides a slight increase in BTE (around 0.5%) for treated biogas than raw biogas. It is possible to obtain a minimum amount of HC and CO emission on average of 2.5% and 3% by burning of lime treated biogas. On the other hand, a moderate NOx and smoke emissions are obtained on a compression ratio of 18 than the other compression ratios.

A. Murugesan, A. Avinash, D. Subramaniam

An Experimental Investigation on DI-CI Engine Characteristics Fueled with Green Synthesized Nanoparticle Doped with Biodiesel Blends

The green fuel technology with eco-amicable processes and novel chemical action is becoming more popular. It is very essential to overcome worldwide problems associated with the environment. In this work, preparation of green synthesized silver nanoparticles (AgNPs) are discussed and experimentally investigated the DI-CI engine characteristics of diesel, B20 (ethyl esters of green biodiesel from neem oilseed) and B20GS20 (B20 doped with the green synthesis of silver nanoparticles from neem leaf extract) as a test fuel. Converting the raw neem oil into the biodiesel by transesterification process using ethanol as a solvent and KOH as a catalyst. Properties of various nanoadditive biodiesel blends and its performance, combustion and emission attributes of DI-CI engine are compared and represented. Neem leaf extracts act as a naturally occurring reagent for producing nanoparticles. With the assist of an ultrasonicator, the bio diesel-diesel blends (B20) doped with green synthesized 20 ppm nanoparticles are prepared. The properties of test fuel are tested and compared with ASTM standards are presented in this paper. The experimental investigations concluded that green synthesized silver nanoparticles act as diesel-green biodiesel blend (B20) additives in diesel engines as the test fuel. At the maximized load condition, in comparison with B20, test fuel enhances the BTE by 1%, significantly reduces the adverse emissions such as HC, CO, and smoke level by 2.46, 3.07, and 2.97%, respectively, and increases NOx by 1.66%. B20GS20 combustion characteristics like peak pressure rise and heat release rate are slightly enhanced by 1 and 1.9% compared to B20.

A. Murugesan, R. Prakash, A. Kumaravel

Thermodynamic Modelling and Experimental Investigation on a CI Engine Operated with Oxy-Hydrogen Gas as the Secondary Fuel

Substitution for diesel in CI engines is an immediate need of the hour, considering fuel scarcity and environmental safety. The usage of oxy-hydrogen (HHO) gas from dry cell electrolyser, as a new source of energy, is gaining an increasing interest worldwide, because of its excellent combustion properties and the ease of retrofitting to the existing engine. In the present work, Taguchi’s design of experiments (DoE) is used to optimize HHO gas production. Further, the obtained results were reviewed using grey relational analysis (GRA) and analysis of variance (ANOVA). The operational parametric studies of the optimized electrolyser were conducted. Performance, emission and combustion characteristics with HHO gas as dual fuel in CI engine were also performed. The lubricating oil and deposit study in dual-fuel operation were conducted to understand the effect of HHO gas in engines. The combustion characteristics of a CI engine, operating in dual-fuel mode with diesel and oxy-hydrogen gas, were predicted by a zero-dimensional two-zone model. A double Wiebe function was used to estimate the mass fraction burned (MFB) in the premixed and diffused stages of combustion. The estimated MFB was used to calculate the heat released. The equations were solved in MATLAB®, and Eulerian approach was used to solve the differential equations. The theoretical results of properties such as in-cylinder pressure, heat release rate and cumulative heat release were compared against the respective experimental values, which showed a good concurrence. Also, the average and zone-wise temperatures with respect to crank angle were determined and plotted. The good agreement between the theoretical and experimental values may be attributed to the use of different form factors in the premixed and diffused stages.

P. V. Manu, T. R. Navaneeth Kishan, S. Jayaraj

Potential Use of Low-Rank High-Ash Indian Coals Through Gasification Route

Higher ash content in solid fuels poses difficulties in ash handling processes and leads to degradation of equipment efficiency due to low carbon content. The potential of low-rank energy carriers when gasified can be predicted using a thermodynamic model in terms of the upper limit of syngas composition and the process efficiency. A combined two-phase thermodynamic model has been developed incorporating both homogeneous and heterogeneous reactions, assuming it to depict the gasification process on macro-scale. Five typical Indian high-ash coal samples have been selected whose ash content varies from 43.40% to 56.53% on % wt. dry basis. The developed model is then used on these coal samples to predict its gas composition, calorific value of syngas and the optimum operating equivalence ratio. The effect of moisture content and enriched air is also presented. The cold gas efficiency with air varies from 71.3 to 76.3%, whereas it ranges from 78.63 to 84.2% when gasified with 100% O2. Such high efficiency values show that gasification can be an alternative to exploit the energy content of low-rank coals. A clever investigation of the process thermodynamics would be a first attempt in this direction.

Taha Y. Poonawala, Parth D. Shah, Salim A. Channiwala

Bio-methane Generation from Anaerobic Co-digestion of Eichhornia (Water Hyacinth) and Kitchen Edible Material Ravage and Waste Paper with Pond Sludge and Cow Compost by Using Chemical Pretreatment

The essential objective of this paper was to research and look at creation of biogas from differed wellsprings of squander material. The Policy of Renewable energy imagines that 5% of complete vitality creation should be accomplished through 2015 and 10% through 2020 Tasnim et al. (Renew Energy 109:434, 2017 [1]). This effort centres on the similar investigation of the generation of biogas by anaerobic co-processing using deserted assets of biomass. Materials under investigation were waste paper, Kitchen edible material ravage, cow compost, pond sludge and Eichhornia (water hyacinth). Examinations were directed under mesophilic condition (42 °C) with 2.0 wt% NaOH and Ca (OH)2 to get the alluring pH. The stacking proportion of each group was kept up as 1:1 on the two investigations. Cakes of cow dung and edible material ravage revealed promising auspicious till about the 140th hour following falling generation of biogas. Entire mixture of 812 ml constituted of chemically treated 1 Litre of Eichhornia (water hyacinth), cow compost and pond sludge. The biogas produced after 900 h of anaerobic decomposition of the above-mentioned mixture consisted of 67.8% CH4, 13% carbon monoxide and 28.9% other gases, while the same mixture contents with volume of 335 ml, without chemical pretreatment produced 62.5% methane, 18.9% CO and 24% other gases within the same time frame. Outcomes signified that adding of pond sludge and waste paper with the generally utilized cow compost by chemically pretreated can promote to boost reaction, augmented generation and enhanced methane content.

Sonam Sandhu, Rajneesh Kaushal

Experimental Study of a Diesel Engine Using Soybean-Based Biodiesel and Diesel Blends

The energy need is rising steadily because of accelerated manufacturing development, growing population, increasing urbanisation and economic growth in the world. A huge quantity of fuel is required from various resources to fulfil the energy need. Thus, a large amount of fossil fuels is burned to fulfil the energy demand, which has caused some hazardous effects on the environment. In the present, biodiesel is a very demanding renewable alternative fuel of diesel due to its accessibility, relatively easier manufacturing process and superior fuel characteristics such as storage safety and complete combustion. In this experiment, the effects of diesel-biodiesel blends on the performance of the diesel engine have been carried out experimentally at various loads. The experiment has been conducted on 4-stroke, single-cylinder, water-cooled, variable compression ratio and multi-fuel diesel engine. The engine is fuelled with soybean oil-based biodiesel blends. The fuel is blended in various blend ratios, i.e. D80B20 (80% diesel–20% biodiesel), D70B30 (70% diesel–30% biodiesel) and pure diesel are used to fuel the single-cylinder engine. Also, the performance of the engine is tested by varying the compression ratio. The values of compression ratio, i.e. CR14, CR16, CR18 and CR20, are considered for testing the engine performance. During the engine test, both indicated characteristics and experimental characteristics are found out for each blend and compression ratio. The results reveal that the blend containing 30% soybean biodiesel has better performance than pure diesel. The performance of the engine, fuelled with biodiesel blend B30, is optimum at CR16.

Arun Rathi, Rajneesh Kaushal

Performance Analysis of Soybean Oil Blended Diesel Fuelled DI Engine by Varying Compression Ratio

Biodiesel has become a prime source of alternative fuels and is becoming a big source of renewable energy for the future. Various alternative fuels have been studied whether partially/completely to replace diesel fuel. Soybeans-based vegetable oils are proposed as promising alternatives to diesel because they are manufactured in rural areas. Oil manufactured from soybean may provide opportunities for self-employment. The impact of biodiesel/diesel blends on engine performance and combustion, have performed experimentally at various speeds and loads. Volumetric percentage of diesel/biodiesel blends: D80B20 (80% diesel-20% biodiesel) and D70B30 (70% diesel-30% biodiesel) were ready to power a single-cylinder DI engine. The test has been done on four strokes, single-cylinder, multi-fuel, VCR engine. The prepared samples were tested at a constant speed in CI engine by varying the loads and compared with the diesel fuel additive; the engine results show a decrease in BTE and an increase in BSFC with an increase of biodiesel ratio in the mixtures. It is found out that BSFC for D70B30 is more. The engine performance in the case of 30% biodiesel blend is better. The emission of Exhaust Gas Temperature (EGT) in biodiesel blend reduces than diesel. Due to low ignition delay and low calorific value of biodiesel, the cylinder pressure is slightly reduced for higher percentage of biodiesel in the blend. At different loads, a consequent decrease in Mechanical Efficiency and Engine Speed (RPM) is observed with an increase in engine torque. All the characteristics of the engine performance are displayed graphically.

Pradeep Kumar Sonkar, Rajneesh Kaushal

Internal Combustion Engine and Emission


Design and Development of Wave Rotor Technology for an Automotive Diesel Engine

As internal combustion engines are getting downsized and require lower mass flow rate, their cycle efficiency drops significantly. Such small engines with swept volume (~435 cc) are used in three wheelers in our country. Around 2,32,000 three wheelers are sold in Tamil Nadu alone, and thus the auto rickshaw is an ever-growing industry for public transport in India. The decrease in cycle efficiency hampers good performance and results in major pollutant formations. The naturally aspirated engines used in all the rickshaws consume more fuel, are bigger in size and give out more emissions. A novel wave rotor technology developed in the past few decades is a germane solution to the fuel efficiency and emissions conundrum. The Greaves single-cylinder 435 cc engine was modelled on SOLIDWORKS software and then simulated on Converge CFD software. The results were compared with experimental testing of the engine. With the simulation result validated for the engine, the engine was simulated with boosted air pressure of 2 bar. This boosted pressure value was obtained from previous experimentation done on Comprex. The simulation result obtained at boosted pressure showed significant increase in efficiency of the engine with peak pressure of 129.25 bar and reduction in CO emissions.

J. Thangaraja, Datar Shantanu, Mayuresh Bhosale, Razi Nalim

Study of Emission Characteristics of a CI Engine Fueled with Water Diesel Emulsion Fuel

The CI engine exhaust contains several hazardous components that need to be minimized. Water diesel emulsion (WDE) fuel controls the emission of such poisonous gases and helps to minimize them. WDE fuel gives several special advantages including immediate reductions in emissions from all the generations of CI engines without changing its engine hardware. For India, where most of the CI engines are more than 15 years old, WDE could contribute in the instantaneous enhancement in air quality. The characteristics which help to make water diesel emulsion technique preferable and practical option for controlling emission and enhancement in air standard are presented and discussed. The aim of this investigation is to formulate stable WDE fuel. To analyze characteristics of emission, CI engine with single cylinder is utilized which is equipped with an eddy current dynamometer, gas analyzer, and smoke meter. Three different emulsion fuels with different water content (0, 5, and 10%) were prepared with proper surfactant and their characteristics were analyzed. At all loading conditions, WDE fuel with 10% water content exhibits appreciable reduction in NOx level and smoke opacity in emission with minimum penalty in other emissions.

Bhupendra S. Patil, Rajesh C. Iyer

Comparison of Concurrent Reduction of Smoke and NOx Emission Techniques

In the present research, the different simultaneous reductions of oxides of nitrogen (NOx) as well as smoke are compared. The methods are gasoline fumigation (GF), exhaust gas after treatment using water scrubbing (EGAT) method and gasoline fumigation along with nanoadditive. Gasoline fumigation was achieved by controlling the electronic injector fitted at the intake manifold using the open ECU software. An exhaust management set-up is invented, which is attached to the tailpipe of the engine. This precedes the exhaust and injects water in the tailpipe and sends it over the silica gel chamber. The aluminium oxide nanoliquid was blended with diesel in mass fractions of 50 ppm. The features of a single direct injection (DI) diesel engine are studied for GF, EGAT and gasoline fumigation along with 50 ppm nanodiesel blend (50AONP – D +GF). EGAT shows higher NOx and smoke emission reductions compared than diesel, gasoline fumigation and gasoline fumigation with nanoadditives. The simultaneous reduction in NOx and smoke, increase in BTE at high power and reduction in CO and HC when nanoadditive is used, shows gasoline fumigation as the effective method for diesel engines.

M. Bharathiraja, Ragupathy Karu, P. Arjunraj, P. D. Jeyakumar

Performance and Emission Characteristics of an Engine Generator for Different Fuels

The aim of the present work is to determine the performance and emission characteristics of little genie engine generator (genset) at various engine loads (0, 250, 500, 1000 and 1500 Watts) for different fuels: kerosene, petrol, diesel and liquid petroleum gas (LPG). This engine generator is manufactured by Birla Yamaha (India) and is mostly used in villages, small cities and low-cost industries for generation of electricity. The exhaust emissions of the engine such as CO, CO2, O2, NO and HC are measured with a gas analyzer. Here, LPG is found as the high-performance fuel of the engine.

Saurav Sagar, N. K. Singh, N. S. Maurya

Carburetion and Port Fuel Injection Metering Strategies for Natural Gas Spark-Ignited Engine

The effects of carburetion and port fuel injection (PFI) metering techniques were experimented on naturally aspirated twin-cylinder spark-ignited (SI) engine fuelled with compressed natural gas (CNG). It was operated under full throttle condition at varying speeds ranging from 920 to 3400 rpm for the compression ratio 11.5:1. The performance, emission and combustion parameters were assessed and compared. The carburetion was set at 0.9 bar, while the PFI was set to 5 bar working pressure. A dedicated electronic control unit (ECU) was used for controlling the engine parameters. Comparing with carburetion, the PFI produced maximum brake thermal efficiency of 27.2% at 1800 rpm. Due to the increased volumetric efficiency performance of PFI system, there was notable reduction in hydrocarbon (HC) as well as carbon monoxide (CO) emissions in comparison with carburetion. There was a noticeable increase in nitric oxide (NO) emission as a result of complete combustion. The enhanced combustion process with PFI has improved peak pressure with reduced cyclic variations. On a whole, PFI system had excelled carburetion system towards better mixture formation.

Jim Alexander, E. Porpatham

Evaluation of Performance and Emission Characteristics on Diesel Engine Fueled by Diesel–Algae Biodiesel Blend with Ignition Enhancing Additives

Algae offer an appealing source for creating inexhaustible and feasible biofuels to diesel engine. Researchers evaluated the performance of algae and microalgae biodiesel in various types of diesel engine and reported that engine characteristics of algae biodiesel (B20 blend) are closer to baseline (diesel) fuel but NOX emission is increased for algae and microalgae biodiesel blend in diesel engine. With the purpose to reduce the NOX emission, addition of ignition promoting additive with B20 blend is viable solution without engine modification. In this study, B20 (80% of diesel and 20% algae biodiesel on volume basis) is blended with 5% of di-ethyl ether (DEE), 2-ethylhexyl nitrate (2-EHN) and di-tertiary butyl peroxide (DTBP), namely B20 + 5% DEE, B20 + 5% 2-EHN and B20 + 5% DTBP, respectively, and the impact of the ignition improvers on the engine performance and emission characteristics of biodiesel-fueled diesel engine was examined for the fuel blends. The outcomes demonstrated that the addition of DEE, 2-EHN and DTBP in biodiesel enhanced the performance and emission characteristics of DICI engine and this study concluded that the DTBP can be utilized as promising ignition enhancer for diesel–algae biodiesel blend to compare with DEE and 2-EHN.

A. Gurusamy, A. A. Muhammad Irfan, E. R. Sivakumar, P. Purushothaman

Investigations of Combustion, Performance, and Emission Characteristics of Gasoline Engine Operated on Blends of Gasoline with Ethanol and n-Butanol

World today faces two major challenges of fast depleting petroleum-based fuels and environmental threats due to combustion of these fuels on large scale. World is conquering this challenge, and alternative fuel’s suitability in current internal combustion engines is being realized. Alcoholic fuels have been suggested in this regard, and primary alcohols like methanol and ethanol are rigorously studied. Current study has attempted the comparative analysis of gasoline-ethanol and gasoline-n-butanol blend in a specified petrol engine. Experiments are performed by varying speeds from 1200 to 1800 rpm for three blends of ethanol and n-butanol viz 10%, 20% and 30% vol., respectively. In-cylinder peak pressure was found maximum for gasoline followed by Bu30. Greater mass fraction burned (MFB) values were shown by Bu20 and Bu30. Heat release rates were also maximum for high n-butanol blends. Despite of this, high n-butanol blend found short in BTE and BSFC. However, low blend Bu10 along with E10 and E20 exhibited slightly more (nearly 4% more) BTE and BSFC than gasoline. High octane rating and oxygen content might be the cause for bettered BTE and BSFC. Emissions of HC and CO were more for all blends than for gasoline. This might be due to less in-cylinder temperatures. CO2 emissions remained lower for blends.

M. S. Sawant, S. P. Wategave, N. R. Banapurmath, R. S. Hosmath

Effect of Operating Parameters on the Performance and Emission of a Diesel Engine Fuelled with Diesel–Methanol Blend

The basic and primary fuel consumption rate of India is growing at a large rate. Methanol has the potential to satisfy the alternate fuel requirement of the Indian economy. A Kirloskar SV1 model single cylinder, water cooled four stroke direct injection diesel engine is used to measure brake thermal efficiency, Brake specific energy consumption, exhaust gas temperature, brake mean effective pressure, carbon monoxide, nitrogen oxides, hydrocarbons and smoke. In this study, an experiment was conducted on diesel engine by blending methanol and diesel in a particular ratio of 15:85, respectively. The engine parameters like compression ratio, injection pressure and injection timing were altered with respect to each other and compared with the behaviour of diesel fuelled engine. As a result, there is a desirable change in the emission and engine performance. BTE shows a significant increase with corresponding increase in compression ratio. BSEC was decreased which can be due to the increased brake mean effective pressure. Higher injection pressure means that the fuel and air gets mixed very well inside the cylinder. This leads to better combustion and hence the amount of fuel remaining unburnt decreases. Compression ratio and injection pressure are the most significant factors for emission characteristics.

M. R. Sumanlal, Vineeth Satheesh, Vishal Dilip, J. Navaneeth, M. V. Yadhukrishnan

Fuel Injection Pressure and Combustion Chamber Geometry Effects on the Performance and Emission Characteristics of Diesel Fueled CI Engine with EGR

Nowadays automotive industries and IC engine researchers are highly in verge of developing clean emission technologies with lower fuel consumption. The swirl chamber creates a pollution-free environment and eventually reduces the usage of fossil fuels. The time required for fusing the air and fuel, in a water-cooled direct injection diesel engine, is of the order less than 10 ms. In this research, the burn rate of the engine is enhanced by modifying piston bowl design of a swirl chamber. Three modified piston bowl designs namely: chamber-A (CH-A), chamber-B (CH-B) and chamber-C (CH-C), that uses diesel as the primary fuel were developed with a focus on reducing harmful exhaust emission while maintaining high brake thermal efficiency (BTE) and low specific fuel consumption (SFC). The present investigation examines the impact of injection pressures on performance, emission and combustion characteristics of the single cylinder four-stroke direct injection CI diesel engine (Variable compression ratio [VCR] engine) with these three piston bowl designs. In the current exploration, direct injection diesel engine, at 1500 rpm, with varied fuel injection pressures (IP) (600–1400 bar) and 15% EGR were studied using Diesel-RK simulation tool and the results were analyzed against the experimental values. From the simulation result, the specific fuel consumption (SFC) and nitrogen oxide (NOx) of chamber-A was slightly higher than the other two chambers and simultaneous decrease in particulate matter (PM) and ignition delay (ID) with and without EGR mode was observed. Furthermore the results indicated that EGR led to an increase in SFC and BTE. The experiments were performed using chamber-A and standard piston bowl design with and without exhaust gas recirculation (EGR) mode. With 15% of EGR, the percentage decrease in BTE was up to 2% at quarter load condition and nearly the same at full load condition. The EGR caused a reduction in exhaust gas temperature. Thus, it has a potential to reduce 60% of NOx discharge at full load condition and simultaneously rises the SFC, PM & ID marginally.

V. D. Tamilarasan, T. Ramesh Kumar

Experimental Studies on the Effect of Varying Rates of Part-Cooled EGR in High Pressure Loop on an MPFI Engine Under Variable Speed Operation

Researches in automobile sector around the globe are focused on meeting the currently proposed emission norms. Exhaust gas recirculation is one pre-treatment technique that has been found effective in enhancing the combustion and emission characteristics of IC engines and regulating the emission of nitrogen oxides. The present work analyses the effect produced by different rates of partially cooled EGR in a high pressure loop on a multi-cylinder MPFI gasoline engine. Three flow rates of EGR—12%, 18% and 24%—have been studied, and the impact produced on thermal efficiency, specific fuel consumption and emission of macropollutants of the test engine has been analysed under variable speed operation in comparison with normal operation of the engine without recirculation. The temperature of recirculated exhaust gas is so maintained as not to have a negative influence on the fuel consumption characteristics. A reduction in specific fuel consumption is observed which results in a marginal improvement of brake thermal efficiency alongside the advantage obtained in the emissions of the engine. The study proves that the advantages of EGR addition are limited to around 18% above to which the cyclic variations and misfires become predominant, deteriorating the performance and emissions of the test engine.

Libin P. Oommen, G. N. Kumar

Investigation of Reverse Flow Slinger Combustor with Methanol

This paper investigates the performance of a recently developed reverse flow slinger combustor with methanol. The study has been undertaken with an aim of developing an effective way of burning methanol in gas turbine engines. Methanol is seen as a future alternative to fossil fuels for power generation because of its clean-burning, renewable, and sustainable nature. However, its combustion in gas turbine engines imposes several technical challenges due to its relatively different properties compared to conventional hydrocarbon fuels, such as low calorific value and low viscosity. The novel combustor employed in the current study potentially provides a viable solution for methanol combustion in stationary gas turbines. The combustor design facilitates internal preheating of combustion air from the exhaust products and enhances the flame stability and ignition characteristics, particularly at lean conditions. The combustor performance was investigated with methanol and stable combustion was achieved at very low fuel–air ratio of 0.022. Ultra-low levels of NOx and CO emissions were obtained with them being less than 5 ppm and 1500 ppm, respectively. Unburned hydrocarbons at the combustor exit were found to be less than 0.5% (vol).

Pooja Nema, Abhishek Dubey, Abhijit Kushari

Experimental Analysis of Performance and Emissions of a Diesel Engine Fueled with Diesel–Water Emulsions

In this work, diesel–water emulsification to reduce the NOx emissions and unburnt fuel was attempted. Two different diesel–water emulsions along with selected surfactants which are “92% Diesel, 5.5% Water, 1% Tween 20, 1.5% Span 80” and “90% Diesel 7.5% Water, 1% Tween 20, 1.5% Span 80” used for the experimentation work. These two emulsified diesel fuel variants are installed and subjected to testing on the water-cooled diesel engine under variable load condition and at a constant motor speed of 1500 rpm. The engine performance and emissions data of conventional diesel fuel and two diesel–water emulsified fuel variants mentioned above are obtained and compared. The amount of NOx was lower in the emissions of the engine compared to when a conventional diesel fuel is used, yet the engine performance was not compromised even though there is reduction in peak in-cylinder temperature.

V. Abhinay, S. V. S. S. R. Krishna P, T. Karthikeya Sharma, G. Ambaprasad Rao

Enhancement of Hydrogen Energy Share in an Automotive Compression Ignition Engine Using EGR

The experimental study was performed on a single-cylinder, four-stroke automotive CI engine. The hydrogen gas was inducted into the intake system of engine and diesel was inducted directly inside the cylinder of diesel engine. The optimum hydrogen energy share (HES) without knocking in the hydrogen-diesel-fueled engine at the speed of 2400 rpm with maximum torque is limited to 57%. The hydrogen energy share (HES) without knocking is extended to 65% using 25% exhaust gas recirculation (EGR). Brake thermal efficiency with EGR increases significantly. The emissions of NOx decreased to zero level with EGR. The zero level of HC emission was achieved with and without EGR. CO emission also lower compared to without EGR. The hydrogen-fueled diesel engine with EGR could operate with higher hydrogen energy share with lower emissions compared to conventional mode.

Anilkumar Shere, K. A. Subramanian

Effect of Valve Timing on Performance and Emission Characteristics of Producer Gas Fired S.I. Engine

In the face of today’s increasing use of energy, the research on alternative fuels for internal combustion engine has become essential due to depletion of conventional fuels and its major contribution for pollutants. Hence, development of alternate fuel fired S.I. engines has become a necessity to quench the current and future demands rising in this sector. Various attempts have been made to utilize green energy technologies as an alternative fuel for conventional fuels substitution. Coal/biomass gasification seems to be one the alternative solutions for the energy demand with minimum emissions and captive power generation, too. Looking to this fact, the present work basically focusses on digital simulation of producer gas fired S.I. engine to estimate the performance and emissions of a laboratory scale, four-cylinder, S.I. engine operating at the speed of 1500 rpm and having power rating of 15 kWe by considering heat transfer, progressive combustion, and dissociation of combustible products. Effect of intake valve (12° BTDC—28° BTDC) and exhaust valve timing (14° ATDC—30° ATDC) has been studied for their impact on engine performance and emissions. By considering power, efficiency, and emissions, most optimal combinations of valve timing seem to be IVO as 20° BTDC and EVC as 30° ATDC.

Parth D. Shah, Taha Y. Poonawala, Salim A. Channiwala

Influence of Electronically Controlled Hot and Cold External ReBreathing System in DI-CI Diesel Engine for Reducing NOx Emission

The World Health Organization published a report, saying that diesel fumes do cause cancer; this is due to higher levels of nitrogen oxides and particulate matter diffused with air. In an investigation point of view, most of the researcher’s accepting that external rebreathing system is the successful way of reducing the NOx in the diesel engine. This paper focused on comparing the hot and cold external rebreathing system used to reduce NOx emission. A one-cylinder four-stroke H2O-cooled DI-CI engine coupled with an eddy current dynamometer equipped with electronics-based Ethernet-controlled digitalized hot and cold external rebreathing system was used to analyze the percentage of EGR admitted to the engine. The present experimental investigation is carried out compared to the baseline data with 10% hot and cold rebreathing system. The experimental result shows the brake thermal efficiency of hot EGR 1% increases compared to cold EGR and 1.5% increased without EGR. Emissions like HC, CO, CO2, and NOx are reduced 14.21%, 12.5%, 6.12%, and 48%, respectively, and smoke level increased 7.26% compared the baseline data of the diesel engine without rebreathing system. The related information of the present work with other researchers’ works is detailed in the literature. Overall, the experimental results proved that combust gases will be advantageous in promoting quick auto-ignition of mixed air/fuel, and cooled burned gases would be accepted to obtain already mixed air/fuel mixture.

C. Ramesh, A. Murugesan, G. Mylsami

Use of Chemical Scrubbing Method to Minimise the Pollutants

In present study, a low-cost device has been developed to reduce the pollutant coming out of petrol engine. The exhaust gases such as carbon dioxide, sulphur oxides and nitrogen oxide have been reduced. The pollutant gases coming out of petrol engine are allowed to pass through an absorbent material. The absorbent material absorbs some amount of exhaust gases. The remaining amount of gases reacts with the chemical sprayed on the absorbent material. The different kind of aqueous salts has been formed as the exhaust gases react with the NaOH. The quantitative analysis of aqueous salts has been performed to determine the quantity of pollutant before and after using the device. The results show that the amount of pollutants in exhaust gas has been reduced after attaching the device to the exhaust pipe.

Jasbir Singh, Dipesh Popli, Harshit Nailwal, Himanshu

Performance Characteristics and Emission Analysis of Nano Additives Added Mustard Oil Biodiesel in a Compression Ignition Engine with EGR

Increase in the crude oil price and the demand for crude oil in the non-petroleum producing countries forces them to search for an alternative source of fuel to use. It has been found that the biodiesel obtained from the vegetable oils blended with diesel can work in the Compression Ignition engine without any modification up to certain volumetric composition. Mustard oil was extracted from the plants of Brassica juncea was taken for the preparation of biodiesel by trans-esterification method. The prepared mustard oil biodiesel was blended with diesel in the ratio of 5, 10, and 15% and added with Al2O3 nanoparticles as an additive. The prepared samples were tested in a constant speed CI engine by varying the load to compare its performance and emission characteristics with that of diesel. It has been found from the results that the carbon monoxide (CO) and Hydro Carbon (HC) and smoke emissions were decreased and the Nitrogen Oxides (N0X) emissions were increased with an increase in the blend. The presence of the oxygen content in the blend is the reason for the enhancement of the combustion process and the reduction of the HC, CO, and smoke emissions. Further, the attempt to reduce the N0X emissions was carried out with the help of the 10% of EGR.

Govindaraj Elavarasan, P. Rajakrishnamoorthy, Muthu Kannan, Duraisamy Karthikeyan, C. G. Saravanan

Aerospace Flame and Combustion


Comparative Acoustic Analysis of Modified Unmanned Aerial Vehicle’s Propeller

Propeller’s noise reduction is a prime technique in complicated application-oriented unmanned aerial vehicles (UAVs) because noise is the main targeted input in radar signature. Propeller vortices are vital in the noise generation, so reduction of vortices may chance to reduce the propeller noise. Thus, in this work suggested the various edge modifications on propeller for noise reduction with the help of Computational Fluid Dynamics (CFD) analysis. Totally, six different propellers are modeled by using CATIA, in which the base propeller dimensions are 4.5 inch in pitch and 5 inch in diameter. Primarily, the noise reduction techniques used in this works are located in the various cuts such as saw-tooth cut, curvy cut, aerofoil cut at both leading and trailing edges of a propeller. Acoustic prediction on rotor through CFD is more complicated, so advanced cum flexible simulation tool must be required for the attainment of an acceptable solution. Hence, ANSYS Fluent 16.2 is used for perfect prediction for the comparative acoustic analyses of UAV’s propeller with and without edge modifications, and thereby, the optimized model is suggested for complex UAVs.

R. Vijayanandh, M. Ramesh, K. Venkatesan, G. Raj Kumar, M. Senthil Kumar, R. Rajkumar

Investigation of Nature of Cyclic Combustion Variations in RCCI Engine

This paper presents the investigation of the nature of cyclic combustion variations in gasoline–diesel RCCI engine. An automotive diesel engine is modified with suitable hardware modifications and instrumentation to operate it in reactivity controlled compression ignition (RCCI) combustion mode. A development electronic control unit (ECU) is used to control the fuel injection events. The experiments were performed at a constant engine speed of 1500 rpm and engine load of 1.5 bar BMEP for various diesel injection timings with single and double injection strategy. In-cylinder pressure history of 1000 consecutive engine cycles is recorded for combustion stability analysis. The return map technique is used for determining the nature of combustion stability in total heat release (THR) of gasoline–diesel RCCI engine. The results depict the presence of randomness for retarded injection timings and correlations for advanced injection timings where cyclic variations are too high.

Ajay Singh, Mohit Raj Saxena, Rakesh Kumar Maurya

Computational Studies on Combustion Instabilities for Various Configurations of Afterburner

Capturing and simulating combustion instabilities in afterburner, leading to screech, is very difficult. Carrying out the transient analysis requires large computational facilities and there is a limitation of considering the reverse effect of acoustics on flow and combustion. A novel method of carrying out steady-state CFD analysis followed by acoustic analysis, to capture the acoustic cavity modes for different afterburner models was considered for the study to predict the optimum afterburner. Eight afterburners were modelled, with different area ratios, nozzle angles and equivalence ratios. The numerical calculations had been performed, by using ANSYS® Fluent, with realizable k- ε model and SIMPLE algorithm by enabling energy equation. Kerosene (C12H23) was considered as fuel with virtual fuel injectors with species transport for modelling combustion and finite-rate/ eddy dissipation model for solving the multiple simultaneous chemical reactions. Maximum Mach number was observed for the model with an equivalence ratio of 0.58, area ratio of 5.2 and nozzle angle of 6o and with minimum O2 mass fraction of 0.144 and maximum CO2 mass fraction of 0.075 due to complete combustion. The computational results were imported into Actran™ for acoustic analysis. It is found that the 10-20 dB less mean square pressure values; with maximum transmission loss of 75.5 dB at 530 Hz, 70.7 Hz at 990 Hz; was observed for the afterburner model with equivalence ratio of 0.58, area ratio of 5.2 and nozzle angle of 6o, indicating the maximum absorption of acoustic energy and mitigation of screech instabilities for the designed inlet conditions.

Srinivasa Rao Gurrala, Andavan Shaija

Experimental Study of Ignition Delay of Homogeneous Supercritical Fuel Sprays of Dieseline Blend in Constant Volume Combustion Chamber

İn present experimental work, supercritical (SC) fuel spray combustion technology is studied under diesel engine-like operating conditions inside a constant volume combustion chamber. İgnition delay (ID) of SC sprays is measured, analyzed, and compared with conventional diesel sprays under similar operating conditions. İt is found that ID of SC sprays is significantly smaller than liquid diesel sprays at all operating conditions. At typical normal diesel engine operating conditions of 300 bar injection pressure (IP) and 40 bar cylinder air pressure (CP), substantial percentage reduction in ID of SC sprays occurs, which is above 55%. It is further found that SC spray combustion mainly occurs as homogeneous hot air combustion rather than hot surface combustion/ignition. Significant reduction in ID of SC spray as compared to diesel spray would cause a drastic reduction in NOx and homogeneous single-phase combustion of SC spray would consequently result in a substantial reduction in particulate matter (PM) formation. The best combination of experimental conditions in the present study at which maximum percentage reduction in ID occurs (nearly 85.83%) is found to be HST = 673 K, CP = 20 bar, IP = 300 bar. SC spray combustion is a single-phase homogeneous, faster, and cleaner combustion technology for next-generation diesel engines.

Sanaur Rehman, Shah Shahood Alam

Numerical Characterization of Circular and Elliptical Central Port Inverse Jet Diffusion Flame

The paper presents the numerical investigation of flame characterization of Inverse Jet Diffusion Flame (IJDF) using a circumferentially arranged fuel port (CAFP) burner with the elliptical and circular central orifice. The elliptical orifice helps to enhance the ambient air entrainment compared to the circular orifice. The OH mole-fraction contours are used to visualize the flame shape and jet spread in elliptical and circular inverse jet diffusion flame configurations. The jet spread is found to be broader for IJDF with an elliptical central jet as compared with the circular port. Moreover, higher turbulent kinetic energy in the minor axis plane signifies more considerable air-fuel mixing in elliptical CAFP IJDF.

Vishnu Hariharan, Debi Prasad Mishra

Performance Analysis of an LPG Cooking Stove for Improvements and Future Usability Perspective

Liquified Petroleum Gas (LPG) is an economical, clean, and renewable fuel, preferred for domestic cooking around the world. Because of its benefits, its consumption is growing on a large scale in household use for gas stoves. The present study was carried out keeping in view, energy conservation and to explore the possibilities of improving the performance, in particular, the thermal efficiency of LPG gas stove. An experimental test setup was developed as per IS 4246:2002 for testing the gas stove. A commercially available LPG gas stove was selected and tested for thermal efficiency and emissions, as per IS 4246:2002. The average thermal efficiency of 60.7% was measured. The power of the burner was found to be 1.12 kW. A mechanism to change the loading height was fabricated and installed on the gas stove. The thermal efficiency and gas consumption test of the gas stove was evaluated for the following loading heights, 0, 2.5 mm, 5 and 7.5 mm. The optimum loading height was found to be 5 mm, at which the highest thermal efficiency and lowest gas consumption were measured. After the study, it can be concluded that there is scope for improvement in the thermal efficiency of the gas stove using suitable techniques and design modifications. A cookstove usability evaluation was done for usability and technical features on a scale of 1–5, to understand the user and future needs to develop an improved gas stove for urban and rural households.

Rohit Singh Lather

Numerical Analysis of Lean Premixed Micro Scale Swiss Roll Combustor

Present paper discusses the Swiss Roll micro combustion chamber using hydrogen as a fuel, with the primary objective of low emission combustion device for 1 kW gas turbine engine. With micro gas turbines, micro combustion chamber is one of the important components for power generation. Hydrogen was chosen as a fuel as it is having more flammability and lower reaction time than hydrocarbon fuel. Micro combustion chamber was designed and fabricated using numerical analysis having inlet temperature with lean condition of 0.13 equivalent ratio to rich condition of 1.2 equivalence ratio. With the help of ANSYS CFX software using O’Conaire mechanism with Zeldovich NO. Computational fluid dynamic study was made. The results suggest that the combustor performance deteriorates above the equivalence ratio of 0.5, in terms of NOx emissions.

Ronak R. Shah, Digvijay B. Kulshreshtha

Review of Laminar Burning Velocity of Methane–Air Mixtures at High Pressure and Temperature Conditions

The heated diverging channel technique for the measurement of laminar burning velocities was extended to incorporate measurements at elevated pressures. The evaluation of the combined influence of pressure and temperature on the fundamental combustion characteristics of CH4-air flames is realized through the new experimental facility. The laminar burning velocities of CH4-air mixtures at different equivalence ratios are reported for a pressure range (1–5 atm), and elevated temperatures of 350–650 K. The temperature exponent, α presents with the lowest value for marginally rich mixtures (ϕ = 1:1). The non-monotonic behavior of α is replicated at elevated pressures (2–5 atm). PREMIX calculations with commonly employed kinetic models (Aramco 2, GRI Mech 3.0) were compared with the present experiments. The predictions of Aramco 2 mechanism were in excellent agreement with the present measurements at high temperature and pressure conditions.

Robin John Varghese, Harshal Kolekar, Swetha Lakshmy Hariharan, Sudarshan Kumar

Spray Characterization and Structure Analysis in a Model LPP Atomizer

The current research work focuses on spray characterization in a model Lean Premixed and Pre-vaporized (LPP) atomizer that aims to minimize NOx emission in gas turbine combustors. The injector allows cross-stream atomization of two radially injected liquid jets from a central hub due to the crossflowing air within a surrounding annular region. Both non-swirling and swirling air flows were considered. Optical measurement of spray characteristics is reported for a range of aerodynamic Weber number, (Weg ≈ 40–140) and momentum flux ratio, (MFR ≈ 3–7) that ensured that the jet–wall interactions leading to liquid films were avoided prior to completion of the jet breakup. Planar laser sheet imaging of the spray illustrated significantly wider dispersion of the spray droplets and modification in the overall spray structure due to introduction of air swirl upstream of the liquid jets within the atomizer. The droplet size and all three velocity components were measured using a Phase Doppler Particle Analyzer (PDPA) technique. The SMD was found to significantly reduce with increase in Weg for swirling as well as non-swirling crossflows. The tangential and radial velocity of droplets increased under the presence of swirling air as compared to non-swirling crossflow. The proper orthogonal decomposition (POD) analysis of the spray images was done which revealed the dominant structures in spray. The second and third POD modes were found to depict the alternate feature of region with concentrated droplet number density. Spray fluctuations due to unsteady jet breakup become dominant feature over flapping of spray structure for higher Weg.

Shirin Patil, Srikrishna Sahu

Design of Free-Piston Linear Generator

Hydrocarbon fuels have high energy density compared to batteries (reference); hence, converting the energy of fuels through conventional engines into electrical energy with the help of rotary generators is a common practice. But this process involved lot of inefficiencies. Coupling of two new concepts, i.e. free-piston engine and linear electric generation, may prove to be an efficient way and can act as mileage range extender for electric/electrified vehicles. Idea behind this project was to use geometrical parameters of conventional single cylinder diesel engine and check if same parameters can be used for free-piston engine (FPE) using simulations. Conventional diesel engine CFD model was prepared in CONVERGE CFD software and was validated with experimental data. Same engine was then modified to simulate as a free-piston engine and the piston motion was analysed. To check efficient linear electric generation, a simple generator circuit was prepared with help of MATLAB–Simulink module. The electricity output was analysed adding a sample battery into the Simulink circuit. Based on the simulation results obtained, a free-piston layout for simple structure, proper balancing, and linear electric generator to avoid mechanical losses concluded as possible solution for efficient electricity generation

Aditya Purkar, P. R. Dhamangaonkar, K. Muralidharan

Prediction of Heat Losses in Scramjet Vitiator

The total temperature achieved by vitiation of air using hydrogen–oxygen combustion is predicted after heat transfer losses. The adiabatic temperature, combustion products, and its properties are acquired using GASEQ. The heat transfer losses include losses due to convection and radiation of the mixture. The hot jet from individual burner enters the preheater with a velocity, which in turn causes convection to occur from the gas to the surface of the preheater. The convection loss is predicted using basic convection heat transfer equation used for heat transfer of hot gases flowing over a plate. The radiation loss was predicted using the emittance of the combustion products at different temperatures using existing analytical data. The emittance of the mixture is a function of adiabatic temperature of the combustion, chamber pressure, and partial pressure of water vapour in the combustion product. The prediction is compared with experimental total temperature, and calculated using the chamber pressure PO. The predicted total temperature is also compared with thermocouple value in one of the tests. The prediction helps in the design of supersonic combustion experiments which are largely dependent on the total temperature of the preheater. The prediction was used get the total temperatures up to 1100 K in the preheater.

Rocky Simon Pinto, S. Gagana, T. Sree Renganathan, S. M. D. Hamid Ansari, Thiruchengode Mahalingam Muruganandam

CH-PLIF in Horizontal Slab PMMA Laminar Flame

PMMA flames are used as surrogate fuels for fire studies. Horizontal slab PMMA flame is studied here in laminar conditions. In particular, the CH radical field is obtained in a qualitative manner with respect to the luminous flame. CH-PLIF was used to obtain the CH radical field, along with simultaneous imaging of the flame luminosity. This was done at various time instances after ignition, and the change in flame shape and the CH field was observed. It was found that CH field was present in the same zone as the luminous flame. Since the luminosity is due to black body emission from the soot, it can be seen that the CH radicals exist in the same region as the soot region in the PMMA flames. This information along with OH radical field information will be useful for validating computational models for fire prediction.

Poorva Shrivastava, Deepika Ram, Thiruchengode Mahalingam Muruganandam

Numerical Analysis on Effect of Radiation in Laboratory-Scale Hybrid Rocket Motors

In this work, the effect of radiative heat transfer in the performance of a laboratory-scale hybrid rocket motor is investigated numerically. The radiative transport equation was included in the numerical model and was solved using the discrete ordinates method with S6 approximation. In the hybrid rocket motor with radiation model, the radiative heat flux is small compared to other heat fluxes, but the change in net flux due to inclusion of radiative heat flux corresponds to the change in the surface temperature and regression rate in the motor. The net heat flux into the fuel surface increased marginally at the beginning of the motor and decreased downstream in the motor when compared with the model without radiative heat transfer. The temperature and burn rate profiles also follow a similar trend in accordance with net heat flux.

G. Krishna Prasad, Amit Kumar

Characterization of Engine Combustion Flames Using Inverse Abel Transform

The present work involves the development and implementation of a mathematical transformation called inverse Abel transform and its application to diagnostics of reacting flow systems. Chemiluminescence is the phenomenon of emission of light during a chemical reaction. It takes place due to the formation of an intermediate excited state which further stabilizes and produces light. Chemiluminescence has a wide range of applications like analysis of inorganic species in a liquid phase, combustion analysis (concentration of CH* and OH*), glow sticks, etc. In combustion systems particularly, the location of maximum concentration of CH* and OH* is useful as they are considered to be the heat release markers in premixed flames. The concentration field of a given species can be obtained by viewing the reacting zone through an appropriate optical band-pass filter. This filter allows only the wavelength of light emitted by the species of interest. However, such an image contains the concentration of the entire volume, as each pixel captures the integrated light from the entire volume passing through its line of sight. In order to resolve an axisymmetric integrated line of the sight data distribution to one at a given azimuthal plane, a mathematical transformation called inverse Abel transform is used. The IAT takes a 2D projection and reconstructs a slice of the cylindrically symmetric 3D distribution. IAT also plays an important role in analyzing the projection of plasma plumes and flames. The major difficulties in implementing IAT are the discontinuity and its dependence on the first derivative of the original function. The latter is particularly challenging when used with experimental data, which is discrete and can be noisy. In order to remove these difficulties, several methods are available. Presently, a direct discretization method, implemented in MATLAB, is used to calculate the IAT. This method addresses the singularity by modifying a term suitably to avoid division by zero. The implemented algorithm was tested with various trial functions and was seen to provide an acceptable match. Subsequently, image processing of a CH* chemiluminescence data from literature is performed to obtain the azimuthal distribution of CH* relative concentration.

Shashikant Verma, Rajneesh Kaushal

Numerical Simulation


Numerical Investigation of Split Injection Strategy on Performance and Emission Characteristics of Diesel Engine

The present work investigates the effect of split injection and piston bowl geometry on engine performance and emission. A numerical investigation is performed on a single-cylinder DI Diesel engine using AVL FIRE code. Six different configurations of piston bowl along with three injection ratios were considered. The piston bowl geometry is modified by varying the depth and bowl radius keeping bowl volume, compression ratio, engine speed and mass injected invariant. It was noted that the mass of fuel injected as pilot injection got mixed with the air and the mixture became ready for burning prior to the occurrence of the main injection. In addition to this, the role of increasing the pilot injection mass up to 15% along with piston bowl geometry on the in-cylinder mean pressure, temperature, rate of heat release and emission parameter is explored. Further, an optimization study is undertaken for selected eighteen cases and results were evaluated for different injection ratio and piston geometry. The D4R1 cases were found to be optimum on the basis of emission and performance characteristics as it results in the reduction of soot to 16% and NO to 10% compared with single injection.

Ankit Kesharwani, Rajesh Gupta

Multiple Optimizations of Engine Parameters of Single-Cylinder Four-Stroke Direct Injection Diesel Engine Operated on Dual Fuel Mode Using Biodiesel-Treated and Untreated Biogas Combination

In this present work, an experimental investigation was conducted to study the combustion characteristics of a single-cylinder four-stroke water-cooled diesel engine operated on dual fuel mode using Honge oil methyl ester (HOME) and treated/untreated biogas (TBG and UTBG). Engine operation is carried out with varied injection timing, injector opening pressure, and compression ratio, and its influence on the performance, emissions, and combustion characteristics are studied and compared to that of conventional pilot fuel and biogas operation. The treated and untreated biogas composed of 92% and 70% methane, respectively. Biogas is a primary fuel which is well mixed with air using suitable carburetor in the inlet manifold, whereas the pilot fuel (diesel/HOME) is directly injected into the combustion chamber. Experimental investigation showed that with an optimized parameters thermal efficiency for HOME-based operation with TBG resulted in 4.3% decreased thermal efficiency and as far as emission levels are concerned, smoke, CO, and HC levels were increased by 19.4%, 21.2% and 14.5%, respectively, compared to diesel-based dual fuel operation at 80% load. Increased delay period and reduced in-cylinder pressure and heat release rate were observed for HOME-based dual fuel operation. Further, about 79 and 72% fuel saving was achieved for diesel and HOME-based dual fuel operations with TBG at the 80% load. It is also noticed that HOME-biogas combination resulted in smooth engine operation. Hence, their extensive utilization for power generation applications will substitute the way for country energy security.

V. S. Yaliwal, S. R. Daboji, K. N. Patil, M. K. Marikatti, N. R. Banapurmath

Bond Graph Based Modelling of Four-Cylinder In-Line Engine and Study of the Various Engine Characteristics Parameters

The dynamics of the four-cylinder In-line engine is taken into account in this work. Firstly, the motion and thermodynamics equations of the engine model are discussed. The bond graph model of the four-cylinder in-line engine with 1-3-4-2 firing order is developed by using SYMBOLS Shakthi software. The thermodynamic and mechanical phenomena are considered while developing the model of the engine. The various engine characteristics parameters such as crank speed vs. torque developed, speed and acceleration of the crank for different values of J (mass moment of inertia of flywheel), piston stroke length of all cylinders and pressure-volume diagram, etc., are discussed for proposed model of the engine. Also, the piston–cylinder model based on prismatic joint is discussed and its bond graph model is developed.

Rajmeet Singh, Joypreet Singh, Tarun Kumar Bera

Numerical Study of Deflagration to Detonation Transition in 2D and Axisymmetric Detonation Tube with Obstacles Using OpenFOAM

In this study, homogeneous hydrogen-air mixture is numerically investigated in a tube of 1 m length and 50 mm diameter with obstacles by solving two-dimensional compressible Reynolds averaged Navier–Stokes equation with reaction modelling of hydrogen-air combustion, using open-source deflagration to detonation solver ‘ddtFoam’ at OpenFoam platform. Deflagration to detonation transition is observed in the tube at various time and locations depending on obstacle configuration namely the blockage ratio and pitch. Turbulence offered by obstacles result in faster transition from deflagration to detonation. Suitable boundary conditions are assigned, and 2D and axisymmetric numerical simulations are performed and compared. Pressure, temperature, and flame tip location vs. time plots are plotted, and it has been observed that in 2D simulations, lower pitch of the obstacle system results in earlier deflagration to detonation transition, and detonation occurs earlier in axisymmetric simulations than 2D simulations for same configuration of blockages.

Udit Vohra, Rajpreet Singh, Vinayak Bassi, T. K. Jindal, Amarjit Singh

Numerical and Simulation Approach for Design of Variable Valve Actuation Mechanism on Single-Cylinder Diesel Engine

Diesel engine requires continuous improvements not only in performance front but emissions front as well to meet upcoming stringent emission regulations and fuel economy requirements. Challenges to meet future emission standards not only require technological upgradation for combustion optimization, but also requires better engine thermal management with emission and performance. Variable valve actuation (VVA) solutions are effective for combustion quality and temperature management with various timing and lift options. The upcoming emission norms for LCV application engine are very challenging and require significant management of combustion strategies including in cylinder flow control and distribution. The variable valve actuation mechanism is designed considering the assembly constraints to have flexibility of higher intake valve lift and duration compared to existing configuration, suitable to the engine performance requirement. The new design of cam profile is analyzed for kinematic and dynamic performance for variable valve actuation mechanism and compared with existing cam profile performance. The dynamic analysis of whole VVA mechanism is carried out to evaluate lift, velocities and accelerations profile. The purpose of this work is to develop a methodology for design, analysis and evaluation of variable valve actuation systems used for the control of intake valve movement in single-cylinder LCV application diesel engine. The strategy begins with detailed study of existing valvetrain system, assembly layout and design of proposed VVA system using CAD software, and consequently, numerical simulation of components and assembly is carried out within prescribed boundary condition. Engine parameters like fuel efficiency, volumetric efficiency, power output and exhaust emissions depend upon the quantity of air going in the combustion chamber, and this is controlled by opening and closing of inlet and exhaust valves. Due to strict regulations on emission control, controlling the flow through inlet and exhaust valves plays an important role. This paper deals with the design of a variable valve actuation mechanism employing solenoid valves, on a single-cylinder diesel engine. Multibody dynamic analysis of this new mechanism is carried out in MSC ADAMS, the results of which are compared with the conventional valvetrain mechanism. A finite-element structural analysis of the individual components of the mechanism is done in ANSYS 16.0 to verify the integrity of the components under the actuating forces.

Ashish Jain, E. Porpathamn, Sukrut S. Thipse

Determination of Stretch-Corrected Laminar Burning Velocity and Selection of Accurate Analytical Model for Burned Gas Mass Fraction Using Constant Volume Method

Constant volume method of determining laminar burning velocity suffers from the limitation that correction for flame stretch of such flames is difficult. For this reason, the constant pressure method is more widely accepted as an accurate method for determination of laminar burning velocity and not constant volume method. In the present work, a stretch correction method has been proposed to get the unstretched laminar burning velocity by carrying out numerical simulations for combustion in a constant volume bomb using a constant volume method. Also, three analytical models for burned gas mass fraction have been assessed by comparing them with numerical results to select the most accurate analytical model to relate burned gas mass fraction to pressure. Unstretched laminar burning velocity of CH4–air mixture at pressures up to 4 bar has been obtained using constant volume method, and the results have been validated against literature. Luijten’s model for burned gas mass fraction was found to be the most accurate amongst the ones investigated.

Anup Singh, Vikas Jangir, Anjan Ray, M. R. Ravi

A Three-Dimensional Numerical Model to Predict the Performance of a Microcombustion-Based Thermoelectric Generator

The current study presents a three-dimensional numerical model of a combustion-based thermoelectric power generator. The novelty of the proposed work lies in the development of a numerical model to simulate the thermoelectric effect, integrated with combustion, in a CFD environment. The integrated system comprises of a stepped microcombustor, a recirculating cup, and two Bi2Te3 modules. The microcombustor is optimized to give a high thermal output through two backward-facing steps and exhaust gas recirculation, which enhances the flame stability. Further, the integration of the thermoelectric module into the CFD environment and the thermal characteristics and the thermoelectric performance of the system are analyzed. A maximum open-circuit voltage of 7.2 V and a peak power rating of 4.35 W are reported, with a maximum conversion efficiency of 5.39%. The successful integration of the thermoelectric model paves the way for further research in the field of thermoelectric power generation.

B. Aravind, Karan Hiranandani, Sudarshan Kumar

Numerical Investigation on Combustion Characteristics of Premixed H2/Air in Stepped Micro-Combustors

Burning properties of premixed H2/air mixtures in single-stepped micro-combustor were numerically analysed. A detailed H2/air combustion mechanism of with nine species and 21 elementary reactions was used to model the combustion chemistry. Both laminar and turbulent models are considered for the analysis. The effect of inlet velocity (v) and step ratio on combustion characteristics and outer wall temperature (To_w) of combustor was studied. As step ratio is increased, the outer wall temperature of the combustor decreases due to the effect of lesser heat release rate and lesser transfer of heat flux for higher step ratio cases.

Gannena K. S. Raghuram, B. Aravind, E. V. Jithin, Sudarshan Kumar, Ratna Kishore Velamati

Numerical Investigation on Flame Dynamics of Premixed Hydrogen–Air Flame in a Sudden Converging–Diverging Microscale Tube

Two-dimensional transient simulations of premixed hydrogen–air flames in a converging–diverging microscale tube have been performed in the present study. The effect of various thermal wall boundary conditions on flame dynamics is realized. Different flame shape transitions are observed with a change in the flame propagation speed, flame temperature, and heat release rate for different wall heat transfer coefficients. This progression of flame behavior is attributed to the thermal wall coupling and hydrodynamic effect.

Akshit Yadav, B. Aravind, Sudarshan Kumar

Numerical Investigation on the Effect of Wall Preheating on Flame Stability of Stepped Microcombustor

Two-dimensional steady-state simulations to understand the flame stability of a cylindrical backward-facing three-stepped microcombustor with a recirculation cup are performed in the current study. This model is initially validated by using data from preliminary experiments and also ensured the grid independence. The aim of the present study is to understand the effect of heat recirculation on flame stabilization in a stepped combustor. Various heat recirculation cup lengths, ranging from 10 to 50 mm, are considered for the present computation. The results show that an increase in cup length significantly improves the flame stability through mixture preheating. This study indeed helps in developing an optimized combustor that can be used as a heating source for power applications.

Chilanka P. Panicker, Iram Maqbool, B. Aravind, Sudarshan Kumar

Computational Analysis of Intake Manifold Design Variants on Induction Swirl of Single-Cylinder Diesel Engine

Compression ignition diesel engines are the most promising source of power for many stationary and commercial vehicles. The performance of the diesel engine could be improved by the optimum design of the combustion chamber, induction system and exhaust system. In the case of diesel engines, airflow inside the engine cylinder has a considerable influence on the combustion and emission levels of the engine. In this research work, engine performance investigations are carried out by improving air swirl motion by applying guide vanes inside the intake manifold. The effect of guide vane on airflow inside the cylinder is studied by using 3D internal combustion engine simulation software under motored engine conditions with the help of ANSYS-CFX. A single-cylinder diesel engine is modelled to analyse the effect of the design and geometry of guide vane on airflow inside the cylinder. The guide vanes are designed to incorporate into intake pipe of the engine in different geometries. The number of guide vanes and angle of inclination is configured on the basis of simulation. The simulation result shows that the four guide vanes with 180° helix improve in-cylinder airflow characteristics like pressure, velocity and turbulent kinetic energy. The optimized guide vane intake manifold was designed and tested on the designed experimental test set-up. The experimental results show that the swirl ratio is improved from 0.8 for the base model to 1.35 for the modified manifold model. The engine also tested on a test bench with an basic engine intake system and modified intake manifold. The results show that the modified intake manifold reduces specific fuel consumption by 1% and CO and HC emission by 20%.

Dhananjay G. Thombare, Vivek V. Ghare, S. A. Dunung

Computational Fluid Dynamics of Co-axial Unconfined Isothermal Swirling Jets

The topological changes in the recirculation structures that were observed in one of the author’s experimental work have been validated using a numerical technique. In particular, Reynolds Averaged Navier–Stokes (RANS) methodology is employed to simulate the unconfined co-axial isothermal swirl flow field. Two different turbulent models, i.e. k–ε and RSM, are employed to investigate the turbulent flow field for the different Reynolds and swirl number configurations. The streamlines showed good agreement of numerical results with previous experimental results. Further insights into swirling flow field are gained by turbulent kinetic energy field.

Arun Pattanashetti, R. Santhosh

Numerical Study on Sample Thickness Dependence of Fire Response Properties of Polymeric Materials (Charring and Non-charring) in Standard Cone Calorimeter Test

In standard cone calorimeter test fire response properties like time to ignition, peak mass loss rate, time to peak mass loss rate, average mass loss rate and burn out time are of interest. The ASTM 1354 [1] recommends sample thickness of less than 50 mm for the test. However, for thinner samples conditions on the unexposed side of the sample should represent actual conditions in real-life application as the test results may be affected by these conditions. Therefore, in this work, a numerical study is carried out to predict the effect of sample thickness on the fire response parameters of polymeric materials. Polymeric materials are broadly classified as charring (thermoset) and non-charring (thermos-plastic). A representative material in each category, namely CPVC (Chlorinated Polyvinyl Chloride) for charring polymer and PMMA (Poly Methyl Metha-Acrylate) for non-charring is studied. It was noted that properties like the peak mass loss rate, time to peak mass loss rate, average mass loss rate and time to ignition vary with sample thickness for both charring and non-charring polymer. These property values become constant for sample thicknesses beyond a certain value. The variation in properties is dependent on the condition on the backside of the sample. When an aluminium block was assumed to have been placed below the sample, the property variation was different from when an adiabatic condition was assumed. The fire response properties for charring and non-charring materials also exhibited different trends.

Vishal Srivastav, S. Sabarilal, Amit Kumar
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