Recent Trends in Mechanical Engineering

The thermal performance of the trio tube with a dual thermal communication surface heat exchanger (T.T.H. Xr) is analyzed experimentally under the steady-state conditions. Water was used as a working fluid which was available at three different inlet temperatures of cold (C), hot (H), and normal (N). The performance of T.T.H. Xr was compared for the three different flow arrangements of C–H–N, C–H–C, and N–H–C at counter-current flow. The pipes were made of aluminum (inner tube 12.7 mm), copper (intermediate tube 25.4 mm), and GI tube (outer tube 38.1 mm), all pipes having a thickness of 1.5 mm. N–H–C and C–H–C flow arrangements show better heat transfer results compared to C–H–N. The results from experiments were also verified numerically by using the derived equations. A case study was also performed on the results obtained from T.T.H.Xr to compare its performance with the double-tube heat exchanger on the same parameters. It was observed that the pipe length for T.T.H.Xr reduced by ~58.39% compared to the double-tube heat exchanger to extract the same amount of heat transfer from the hot fluid.

Researches on alternate fuels have been gaining the attention of researchers worldwide due to the energy crisis. The fossil fuel sources which are used as the most important resource of energy at present are not enough to meet the increasing energy demand. The whole world is now searching for renewable energy sources. Biodiesel reduces the emission of harmful gases to the environment. Biodiesel was produced from the palm kernel oil using transesterification process. In the present experiment, the engine was fueled with diesel and blends containing 5, 10, and 15% of palm kernel methyl ester. The developed Multi-Input Multi-Output (MIMO) fuzzy model predictions show the correlation coefficients in the range 0.908–0.998 for B15 as it has given a better performance and emission than other blends.

An experimental study has been conducted on the effect of alumina nanoparticles in a DICI (Direct Injection Compression Ignition) engine using cymbopogon flexuosus (lemongrass oil) as fuel. Lemongrass oil (LGO) is extracted from the steam distillation method. This fuel may also be more suitable for diesel engines as an alternate fuel without any transesterification process and engine modification. In this study, three fuels (LGO25, LGO25+ALU50 ppm and LGO25+ALU100 ppm) were tested in a single-cylinder, four-stroke and naturally aspirated diesel engine. From the experimental analysis, it was found that BSFC decreased with an increase in BTE using alumina nanoparticles. The cylinder pressure and heat release rate are higher by 1.66% at LGO25+ALU 50 ppm and 3.7% at LGO25+ALU 100 ppm than LGO25. In the case of emission study, CO, HC and smoke emissions decreased by 16.67% and 25.79%, 5.9% and 12.83%, and 18.94% and 24.7% at LGO25+ALU50 ppm and LGO25+ALU100 ppm concentrations, respectively. NOx emission is increased by 4.95% and 8.27% for LGO25 with 50 ppm and 100 ppm respectively than LGO25.

India is the upcoming industrial revolution, wherein its economy and its fuel consumption have been rising drastically over the past two decades. Petroleum resources are depreciating rapidly in the world biofuels and its blends are the alternative sources for stabilizing demand and supply. Biofuels are eco-friendly and substitute for conventional fuels. When compared to fossil fuels except for nitrogen oxide (NOx) remains emission particles are reduced. For effective reducing, NOx, an Exhaust Gas Recirculation system (EGR) is used as exuberance for a diesel engine. The present investigation carried on Coconut oil blend (CBD20) and Cottonseed oil blend (COBD20) biofuels was prepared by the transesterification process with Al2O3 as catalyst on a diesel engine with different EGR percentage ratios (10, 15, and 20%). In this analysis emission, performance parameters and exhaust gas temperature are measured and compared with two biofuels. In this study compared with neat diesel, EGR shows a better improvement on NOx level and performance levels are greasy.

Brakes are a very vital part of an automobile and with performance, safety and operational life being the most important characteristic, it becomes necessary to have a smooth braking operation throughout its life. The study is focused towards designing, analysing and comparing the result obtained using software Solidworks and ANSYS. Depending upon the usage and purpose, we compare namely two types of brake rotors, drilled and slotted, and suggest where it can be put into use for maximum output by studying its thermal analysis (heat generated) without any structural failures in both the rotors.

Gas turbine effectiveness is mainly having an effect on design of combustor; in this work, studies have been made on different parameters of a typical micro-gas turbine (MGT) that changes the flow inside the burning area. A combustion room is created by utilizing SOLIDWORKS modeling tool and exported to workbench design modeler where computational fluid dynamics analysis is performed by ANSYS fluent. We considered a probability density function (PDF) of LPG fuel with non-premixed combustion mode and activated in radiation model of P-1. Design criterions of chamber height and number of holes on flame tube are varied to get the optimum performance and also considered as two dead zones in between the combustion and dilution zone. The optimized design chamber resulted in a turbine inlet temperature (TIT) of 1301 °K with a velocity of 620 m/s and also is provided with low NOx emission below 54 ppm.

A solar PV-based electric power generation system may be used to exploit renewable energy from the sun in order to supplement the India’s growing need for electricity despite its inherent deficiencies, such as low conversion efficiencies, high capital cost, large land usage and seasonal variation in solar insolation as these techno-economic factors are expected to improve in future. This paper explores the energy performance and environmental impact assessment of a 100 kWp solar PV-based electric power generation system located in India with the help of embodied energy data available in the worldwide literature and by modeling and simulating an equivalent system on SimaPro 8.2 LCA software with ECOINVENT 3.0 as database. As part of this study, a detailed inventory analysis will be carried out on a multi-crystalline silicon (mc-Si) solar PV cell/module-based roof-top electric power generation system for the raw materials extracted, energy inputs used, energy output generated and the number of residuals consequently released to the environment. System’s energy performance results are usually expressed in the form of a widely used energy metric called energy payback time (EPBT). Further, the environmental impact assessment will cover an important category such as global warming potential (GWP). These LCA results help the policy makers and energy planners to compare various power generating options available in India and justify any planned investments in renewable energy sector so that the future demand for electricity is met in a more sustainable manner.

In the present research work, WCO biodiesel with iron oxide nanoparticle samples was considered for DI diesel engine, and its impacts on engine efficiency, combustion, and exhaust gas (emission) characteristics were studied. In this investigation the biodiesel is obtained from WCO by transesterification procedure. The experimental tests were conducted in a CI engine using WCO biodiesel with iron oxide nanoparticles. Engine trials were conducted for all the blends (B20WCOME and B20WCOMEINP75) and the obtained results were compared with diesel. All the tests regarding this work are carried out in a CI engine (diesel engine) at (1500 RPM) constant speed. The biofuel is obtained from WCO and commercially available iron oxide nanoparticles (INP) is used in the present experimental work. INP is added to biodiesel in proportions of 50, 75, and 100 ppm using an Ultrasonicator. The results obtained upon experimentation clearly show that the BTE increases marginally (14.285%) for iron oxide nanoparticles (for 75 ppm) blended WCOME while BSEC decreases (26%) when compared to other blends. The emission levels of oxides of nitrogen (4.87%), carbon oxide (16%), and unburnt hydrocarbons (10%) are marginally decreased as compared to diesel for 75 ppm concentration. From the present experimental work, the blending of iron oxide nanoparticles in WCOME produces most promising results in the CI engine performance with marginal drop in the harmful exhaust gases from CI engines.

Owing to their higher thermal efficiency, fuel economy and power, diesel engines are found to be a successful option in commercial vehicles, either on road or off road. But in diesel engines NOx and smoke emissions are high due to heterogeneous combustion. There is immediate need to exert effort in reducing these harmful emissions and to comply with the stringent emission regulations imposed. It is observed that the requirements in order to reduce NOx and smoke are contradicting. Adaptation of better injection strategy helps in having better tradeoff between NO and smoke. For smoke reduction advancing injection is favorable, and for reducing NOx emission, retardation of injection timing is required. Biodiesel which is eco-friendly is a good renewable alternative fuel to petro-diesel. Various methods are tried for reducing NOx, like retardation of injection, water injection, EGR and so on. In this work multiple injection strategy is used for improving combustion process in CRDI diesel engine for having better compromise in the requirements for the reduction of NOx and smoke emission. Biodiesel blend B20 is prepared from nonedible cotton seed oil using transesterification process. Combustion characteristics are analyzed with a selected multiple injection strategy while retarding injection timings. The strategy consists of three fuel pulses: pilot, main and post. The fuel quantity in pilot is fixed at 10% and that in post is fixed as 0.5 mg per cycle. The pilot pulse is at 10° crank angle before main injection pulse and post is closely coupled with CAD of 3 from main injection. The timing of the main injection along with pilot and post was retarded from the recommended 23° bTDC in intervals of 3°. The parameters related to combustion, like temperature, in-cylinder pressure, rate of pressure rise, cumulative heat release, net heat release and mass fraction of fuel burned, are compared with the baseline data obtained with diesel single injection at 23° bTDC.

Vehicular air pollution causes a huge threat to mankind, especially diesel engines. This study focuses on estimating the pollutant levels of Honge biodiesel in a single-cylinder IC engine which would be ideally suitable for agricultural field. The engine combustion chamber was coated with thin film ceramic material YSZ of 150 μm thickness using plasma spray technique and fuel injection pressure was varied. Honge blend B15 at 230 bar exhibited earlier heat release rate at 4°CA BTDC than diesel in coated engine. Emission reduction of CO, HC and smoke of about 50, 26.5 and 20% was attained for blend B15 compared with diesel and other biodiesel blends at 230 bar. NOx and CO2 emissions were high for Honge biodiesel fuels.

This work proposes palmarosa methyl ester (PME) as a potential alternative energy source as the above species is wildly grown in wetland provinces of India, Bhutan, Afghanistan, including Nepal and China. PME was emulsified with oil fuel at varied volume magnitudes of PME10, PME20, PME30, PME40 and PME100 and their properties were analyzed as per ASTM standards in a single-cylinder ICE at continuous swiftness (1500 rev/min) for its regulated emissions. Test results foretold that the characteristics of PME20 resulted in marginally more elevated amounts of THC (2%), carbon-dioxide (4.1%) and carbon monoxide (3.86%) emissions when equated with diesel.

Owing to power shortage problems, especially in summer, industries are not able to meet their production goals. The concept of deriving electrical power from solar radiation started in early 1990s to get rid of these problems. This concept did not see much of light as water is being used as primary working fluid in all solar devices. Water is considered to be less reactive fluid as it takes more time to get transformed into vapor phase. Because of this reason utilization of solar power is limited to the extent of deriving hot water only instead of steam. Reason for this can also be attributed to certain design deficiencies associated with various inversions of solar devices that are being in use till today. The idea adopted in this work is to evolve an efficient design configuration of solar turbine which converts heat energy that is being extracted from solar energy to mechanical energy. The superiority in this design is utilization of smart fluid in substitute of water. The advantage of using smart fluid is that it vaporizes at relatively low temperature compared to water which needs high temperature to vaporize. Design and development of such device is taken up as research work. This paper brings out the design configuration details along with the principle of operation.

The rapid growth of the society is based on transportation. The global economy hugely depends on surface transports, such as road transport, rail and marine. Diesel engines are the main power source for the transport. There is a huge demand for fossil fuel and strict norms on pollution also compel the researchers to probe in for discovering alternate fuels. Present work investigates the use of high viscous raw vegetable oil, Simarouba glauca (SG oil) oil, in a DICI engine with hydrogen as combustion enhancer. The hydrogen gas is generated by hydrolysis of water and stored in a cylinder. The hydrogen gas is passed by inducting into inlet manifold. Neat vegetable oil was added through high-pressure fuel injection pump and hydrogen was inducted through inlet manifold. The inducted high-energy gaseous fuel was flashed by the intermediate breakdown products of neat oil. It creates a higher temperature ambiance to complete the combustion of bulky molecules of high viscous non-edible oil within a short span of time. The result of the experimentation reveals that the use of H2 certainly enhanced the combustion behavior of neat vegetable oil. In addition, 5% higher brake thermal efficiency, 6% higher EGT, 17% lower smoke, 5% lower CO can be observed from the result. The NOx emission was higher by 17% due to hydrogen inclusion, and 33% reduction in HC emission than diesel. The significance of the investigation reveals that a notable development has been achieved in combustion performance and emission.

Ceramic particles are submerged into the metal to enhance the mechanical properties and also the tear and wear resistance properties and it is named as metal matrix composites (MMCs). MMCs find wide applications in the most advanced high-end engineering industries for structural applications, including aerospace and automobiles. The most easy and economical technique to produce MMCs is by dispersing solid ceramic particulates in a molten metal matrix by means of a stirrer and is named as stir casting method. The resulting mechanical properties are influenced by the uniform combination of ceramic particulates in the molten metal. The Al/SiC MMC is prepared by the mechanical stir casting technique in different compositions by varying the percentage of SiC with 0, 8, 9 and 10. The mechanical properties are evaluated by carrying the tensile and hardness testing of the standard samples as per the ASTM E8/E8 M-08. The strength under tension is maximum for the 10% SiC MMC with the value of 169.94 MPa is achieved. The hardness test results reveal that the 0% SiC has highest hardness number of 57.8 HRB. From the microstructural investigation, it is observed that clustering of the particulates occurs in the 8% SiC and gradual scattering in 9% and 10% SiC.

In laser micro drilling, on changing the focal plane position of the workpiece, there is a significant change in the hole characteristics. This change can be used as an application in some of the industries. In this experiment, the effect of change in focal plane position in the positive, that is upward, direction on the hole parameters is studied and explained. A stainless steel 316 plate is used as the workpiece and a diode-pumped nanosecond pulsed laser is used for micro drilling because of its accuracy and comparatively low cost than picosecond or femtosecond pulsed lasers. It is seen that a significant change in the entry diameter, exit diameter and taper of the hole takes place when the focal plane position is changed. Also, this is carried out at different laser powers.

In modern-day manufacturing process, flexible manufacturing system (FMS) is used for efficient production of parts. In FMS, processing times are important while preparing the production schedule. The manufacturing cost will vary from part to part depending on the processing time and type of machine used. In this paper a case study is considered in which three machines produce three different parts by doing different operations. Each machine can perform all the different operations to produce all the three parts. All the operations can be done in all the three machines. The production timings and corresponding costs vary from machine to machine. The operations sequences for different parts are different. The objective functions considered are minimization of the total flow time, machine workload balancing, maximum workload on machine and minimization of total tool cost. In the first step, we have considered randomly different sequence of operations on different machines, that is, operation index and machine index, and the objective function values are calculated. In the second step, the values of objective function are calculated if a particular machine is not working for manufacturing the three parts, and hence those operations are processed on alternate machines. The observations after calculations are that the total flow time, machine workload, maximum workload on machine and total cost are found to be different for different sequences and due to machine failure these values increased and better operation index and machine index are identified to meet the objective functions.

The present work focuses on optimizing the newly designed ball burning tool using Taguchi analysis method experiment on traditional lathe machine with process parameters for burning. The test piece and ball materials used are Aluminum Alloy 5083 with different percentages of zirconium and high carbon chromium with 6 mm diameter. The levels of parameters of the input process parameters are selected on the basis of one element at a time of the experiment: burning feed, burning rate, and material composition. The response parameters are hardness and roughness of the surface. The main objective of this study is to compare surface roughness and surface hardness values on a workpiece of 100% aluminum alloy and aluminum (99%, 98%) with zirconium (+1%, +2%).

The friction stir welding, abbreviated as FSW, is an innovative solid-state welding process widely used for welding of different metals and their alloys, particularly aluminum and its alloys, in various industries including aerospace and automotive. The tensile properties such as strength under tension of friction stir butt welded joints of Al 6061-T6 alloy sheets under the variable welding (oblique) angle 0°, 30° and 60° are experimentally investigated. The Taguchi L9 experimental method is chosen to construct the numbers of welding experiment. The friction stir welding is performed by considering the process parameters such as rotational speed, tilt angle and feed. The probe is chosen as circular. The operating ranges of process parameters are rotational speed 560, 900 and 1400 rpm, tilt angle 0°, 0.5° and 1° and feed rate 20, 63 and 100 mm/min. The highest strength under tension is obtained as 316 MPa, when the rotational speed is 560 rpm, tilt angle 0.5° and feed rate 63 mm/min. An empirical relationship is generated between the obtained weld joint strength and chosen process parameters. The most effective process parameter is suggested as rotational speed by conducting the regression and ANOVA analysis.

Electro Discharge Machining (EDM) is an unconventional machining process used to make hard metal tools and complex shapes, which are difficult to machine by the conventional machining process. Additive manufacturing is the process of creating a 3D object from a CAD Model by adding one layer over another layer. In this work, it is proposed to fabricate an EDM electrode using Direct Metal Laser Sintering (DMLS) 3D printing process and compare its performance with conventional EDM electrodes in terms of Material Removal Rate (MRR), Tool Wear Rate (TWR), and surface finish. The material used for printing the EDM electrode is aluminum AlSi10 Mg and it is proposed to print it on the Direct Metal Laser Sintering 3D Printing machine. The workpiece material used for the EDM process is steel alloy 681-08 of grade D3. The experiment is conducted on EDM with the DMLS electrode and conventional electrode by varying the peak Current (I), Pulse on time (Ton), and Pulse off time (Toff). A comparison of MRR, TWR, and surface roughness is made varying the above-mentioned parameters.

The automotive sector is keen on using lightweight components with aluminium–steel joints since it leads to reduced fuel consumption and lowered CO2 emission. However, huge variations in the metallurgical properties of aluminium and steel and the use of high energy beam processes such as electron beam welding for fabrication challenge the durability of the resultant joints obtained. The present work establishes the effect of high heat input applied during electron beam welding on the corrosion resistance of 5052 Al–galvanized mild steel lap joints. The study includes microstructural characterization of the weld interfaces using scanning electron microscope (SEM), hardness measurement near the interfacial regions using Vickers’s hardness tester. Results indicated the generation of Al–Fe intermetallic layer at the weld bead–mild steel interface whose width ranged between 2.8 and 10.5 µm from head to foot regions. The composition of the layer was confirmed by the elemental analysis that was done on the layer by Energy Dispersion Spectroscopy which was attached to SEM. The layer had shown a severe impact on the corrosion resistance of the joints when exposed to nitric acid for 24 h following ASTM G 67-04. The joints experienced de-bonding at the interface and have undergone a huge weight loss of 38.9 mg.

In the recent years, friction stir welding (FSW) is playing vital role in automobile and aerodynamic industrial applications. Butt joint configuration is the mainstream of FS welding. In this research work, copper alloys are used for analysis and evaluation by FS welding. The endeavor of this work is to find out the achievability of FS welding process by welding pair of copper plates and study the consequences on the physical properties and mechanical characteristics of welded joints. These geometries are used comprehensively in aerodynamic vehicles, in naval vessels, marines. Since of its weak weldability, it is not comprehensively used in automobile industries. To conquer this barrier, weldability analysis is carried out with Cu 2200 copper alloys using a high-speed steel H13 tool. On further attempts, investigations conceded an influence of elevated revolving speed of tools 900 rpm, axial force 5KN, and welding feed 31.25 mm/sec on tensile strength of 254.25 N/mm2, hardness of 451HRB, and impact test of 34 J of copper alloys joint. Vertical milling machine (VMM) is used for conducting experiments. Determining the good tensile strength is main aim of investigation. The end results show that axial load and tensile strength are inversely related, whereas if tool rotating speed and welding velocity increase, the tensile strength increases.

Thin-walled parts and their precision manufacturing is finding importance in the field of aerospace as well as automobile component manufacturing industries. The value of machining of thin walls like honeycomb structures increases because of the efficiency of such parts in any assembly as robust members which results in reducing the fuel usage and increasing strength of the system. In this part of research work, characterization of surface errors and compensation of errors by offline toolpath modification techniques is discussed. Major concerns of machining in end milling and cutting conditions variables include axial as well as radial depths of cut. After validation of errors by some results of cutting experiments toward predicted using a model, compensation strategies negating the errors are proposed. The results are directly applicable to similar manufacturing of various complex parts.

This paper presents the machining of the nickel sheet using The micro-EDM process. The effect of machining parameters such as pulse on time and gap voltage on the surface integrity parameters such as recast layer thickness, heat affected zone, change in micro-hardness of the workpiece surface and metallurgical transformation in the machined samples has been reported. It is found that ultrasonic vibration given to the workpiece, results in a reduction in the thickness of the recast layer and varies from 7 to 22 µm. The hardness of the fabricated micro-holes improves significantly on the introduction of ultrasonic vibration to the workpiece and was in the range of 116–141HV. In this study, heat-affected zone was not observed in optical as well as in SEM images. The result of the EDS analysis shows that less amount of the residuals of the carbon and oxygen were present over the fabricated holes.

In the present research work, an attempt has been made to study and investigate the weldability of 1.2-mm-thick Ti6-Al-4V alloy sheet using CW (continuous wave) fiber laser. The influences of the variable process parameters such as laser power, weld scanning speed and laser beam diameter on the microstructure, heat-affected zone (HAZ) and mechanical properties of the final butt-welded joints of Ti6-Al-4V sheets have been investigated. All the experiments were performed by using a CW fiber laser having a laser power capacity of 400 W. At different parameter setting conditions such as laser power varying from 200 to 350 W, weld scanning speed from 120 to 200 mm/min and laser beam diameter (0.4 mm) were considered for the experimentation. Based on the experiments weld quality was investigated and characterized in terms of the surface microstructure, micro-hardness, and tensile strength of the welded samples. Morphological studies at different processing conditions were carried out to study their effects on the HAZ (Heat-affected zone) and weld bead geometry. Microscopic images of welded samples clearly show a decrease in weld width of the welded sample with an increase in weld scanning speed and with increasing laser power increase in width was observed. At a scanning speed of 120 mm/min with varying power from 200 to 350 W the size of heat-affected zone (HAZ) are 3.55, 3.70, 3.84, 4.8 mm, and the corresponding size of fusion zones is 1.751 mm, 1.83 mm, 1.921 mm, 2.032 mm, respectively. The trend in micro-hardness variation was observed and it depends on grain size in laser welding. At 350 W laser power with varying speed from 120 to 300 mm/min, the micro-hardness values of the welded sample were found as 387.1, 395, and 403 HV. The tensile strength of the original sample was found to be 940 N/mm2. The testing results of the welded sample have a maximum failure strength of 507 N/mm2 at 350 W and 200 mm/min scanning speed. FESEM images of the welded sample at different processing conditions were used for the study of microstructural changes in the welded zone and the presence of defects at the micro level.

The present work undergoes drill tool wear in drilling of aluminum metal matrix composite materials Al6063/Al2O3 with different drill bits like tin-coated HSS, and TiAlN-coated HSS. HSS tool image is captured before and after drilling by using high-resolution camera when it is fixed in a fabricated setup. Camera solution drill bit image is processed using MATLAB image processing technique and the drill tool wear before machining process and after machining process is obtained drilling processed using MATLAB image processing technique and the drill tool wear before drilling process and after drilling process is obtained drilling experiments are conducted according to Taguchi OA9 design for different parameter combination and tool wear is measured and parameter levels are identified for minimum tool wear by analyzed using Taguchi technique.

This research study presents the development of the quality prototype is critical in any additive manufacturing process as it directly relates to its strength and accuracy. The process of Selective Laser Sintering (SLS) is a versatile and proven process to build quality prototypes. This paper attempts to study the influence of build factors such as part orientation, part bed temperature, and refresh rate (one time used and virgin material by percentage of volume) on the part quality. Taguchi design technique L9 (3 × 3) array settings used. Aimed at the required process factors with least number of experimental runs, the L9 orthogonal array method of experiments prepared using the analysis tools S/N ratio, and Analysis of variance, (ANOVA). The significant control factors are identified for surface roughness, which is necessary for designers and Rapid Prototype machine users.

The Flexible Manufacturing Systems (FMSs) are highly advanced and integrated with manufacturing systems to produce products. It consists of two or more robots with machining cells and automated guided vehicles (AGVs) that will function under computer control. This paper highlights the importance of using loop layout and planning in FMS by decreasing the backtracking distance and distance traveled by Automated Guided Vehicle (AGV). A hybrid metaheuristic algorithm is used in this paper and it is called as Improved Scatter Search Algorithm (ISSA). The FMS Scheduling is a complex phenomenon due to the huge variability in the working parameters. Problems related to scheduling for general cases are characterized as NP-hard. From the given size of the problem, the computation time required to obtain the optimal schedule mostly will produce exponential results. In this research paper, the dispatching rules are merged with PNs and also PNs with hybrid Improved Scatter Search algorithm for FMSs performance measure. These traditional hybrid techniques were used for comparing and verifying simulation results. Finally, the test problems were chosen from the review paper for better comparison and PN hybrids with Improved Scatter Search algorithm provide better result in terms of machine utilization, AGV idle time and makespan considering with and without breakdown condition when it is compared with dispatching rules and Petri net with dispatching rule techniques.

Welding is the most significant component in day-to-day life. Without welding, nothing is possible which relates aircraft to skyrocket, the pipeline to highways, cars to workplace constructions. The major problem related to welding is the occurrence of crack at high temperatures during solidification. Sulphide stress corrosion cracking is a major problem to be analysed during pipeline girth welds. The crack occurs when the test stress level approaches 100%. The crack analysis is an important indicator that reflects the safety status in weld quality. It is also important to understand the severity of the crack formed which will help in improving the safety measures better. This will help in selecting the required materials and the proportion ratio which can handle more stress during testing. The paper is about introducing image processing techniques to analyse the crack region and perform segmentation of crack region.

This paper optimizes the influence of process parameters in drilling and improves the surface finish quality of GFRP (glass fiber reinforced polymer) composites workpiece by using different drill bits such as 8 mm, 10 mm and 12 mm diameter HSS (M2) drill. A series of experiments will be done by varying the different drilling parameters and different spindle speeds, feed rate, and point angle are varied. The impact of parameters and setup correlation of parameters with respect to the Taguchi approach is explained. Validations of the drilling operation for GFRP will be carried out at CITD and its experimental records will be maintained.

Different techniques used to measure the hardness of the grinding wheel based on the grinding wheel surface of various grain sizes and the bond contents present in the wheel structure. Two different techniques are identified to accept entirely their capacity to differentiate the wheels of various commercial hardness. In production industries, hardness of the grinding wheels is one of the key parameters which shows its strength of the grinding wheel. During the operating condition (dynamic), is the first method to easily relate in the workshop, quite more complex to analyze. One more technique in research studies of grinding wheel hardness obtained through statistical analysis result. This research highlights the further improvement of hardness of grinding wheel by combining two different abrasive materials (Al2O3 with Boron nitride). By mixing these two abrasive materials with vitrified bonding system involves the adjustments in order to maintain grinding performance, mainly the wheel hardness, grain holding capability, cutting strength, and wheel safety during the machining. It is a major outcome on mixing proportion, mixing quality, stability, and skill to manage the wheel in its green state during the heat treatment, while the proper composition of the bonding material tends to influence the strength and hardness of the grinding wheel. The present work reports the influence of the hardness of the wheel in terms of improving the wear rate and durability and power consumed during the grinding operation which highly affects the grinding business. The final parts of this article give the improved hardness of the grinding wheel and combined grain topography, wheel morphology would represent a clear step development of grinding wheel technology and that each of value in its own sphere of application in grinding.

Inconel 718 super alloy are highly used in gas turbine, space vehicles, aircraft, nuclear reactors, submarine, petrochemical equipments and other high temperature applications. Due to the excellent mechanical properties, high strength at elevated temperature, it’s hard to machine in traditional machining process. EDM is one of the most suitable techniques to shape this alloy into desire shape. The present study is to investigate the machining characteristics of Inconel 718 material on CNC—EDM using copper and graphite electrodes. Taguchi L9 orthogonal array had been used for design of experiment, where the input parameters are current, Pulse-ON, Pulse-OFF and the experimental outcomes are material removal (MRR). Analysis of variance (ANOVA) is employed to indicate the level of significance of machining parameters.

Friction Stir Welding (FSW) is employed for welding the metal surfaces without changing their phase. The major process variables of FSW are the profile of tooltip including plain or grooved surfaces, rotary speed of the tooltip, the angle of the tool fixed, and the vertical force on the tooltip. This investigation focuses the tooltip geometry with plain surface in FSW of AA6061. Initially conventional cylindrical profile is considered with a predefined tool spinning speed of the tool and compressive force which applied over it axially, for a specific welding application. The factors varied four levels. The stability related, thermal, and transient investigations were performed. The observations were compared with different geometries including two different truncated cone profiles and a hexagonal prismatic profile. The best profile suggested based on the investigation results.

Laser cladding is one of the finest surface modification techniques, to incorporate greater hardness, less wear and corrosion, resistance to oxidation at elevated temperature as well as very low coefficient of friction. Coating with different characteristics can be synthesized by control of the matrix and reinforcement composition of the coating, substrate material, and process parameters of laser beam precisely. Before starting any investigation or research, an investigator have to gather a thorough idea about previous studies in the relevant field. Hence, this article depicts the effect of input parameter on quality of laser cladded coating. In addition, effect on performances and different mechanical properties like microhardness, wear resistance, corrosion resistance, and adhesion strength are also overviewed. Finally, the trends of future development are forecasted which will help a new research scholar to find interest in the field of laser cladded coating and its quality.

AA7075/ZrB2 Aluminium Matrix Composites (AMCs) were successfully fabricated using the in-situ fabrication method. The inorganic salts (K2ZrF6 and KBF4) reacted with molten aluminium at 900 °C and formed ZrB2 inside the melt itself. AMC castings were obtained in different volume fractions (0, 3, 6 and 9%) of ZrB2. The dry sliding wear behaviour of AA7075/ZrB2 in-situ AMCs was evaluated using pin-on-disc wear apparatus. The wear experiments were executed as per Design of Experiments (DoE). The effect of wear parameters such as sliding velocity, sliding distance, content of ZrB2 and normal load on wear rate was analyzed. It was evident that ZrB2 particles influenced the wear resistance of fabricated AMCs. The worn surfaces revealed an increase in number of cracks when sliding velocity, sliding distance and normal load increased. The worn surface of AA7075/ZrB2 AMCs was observed using Field Emission Scanning Electron Microscopy (FESEM). The wear rate was decreased and the corresponding wear resistance was increased when the volume fraction of ZrB2 particles increased in the fabricated AMCs.

Microwave radar absorbing properties are effectively achieved due to the unique structure and electrical properties of nanostructured materials. The main objective of the present work is to show that by utilizing lower weight fractions of MWCNTs an efficient and thin microwave absorber with load bearing capacity can be developed. Fibre reinforced polymer (FRP) nanocomposites for radar absorbing applications in the X-band (8.2–12.4 GHz) were prepared using MWCNTs as dielectric lossy material. The complex permittivity values obtained from Vector Network Analyzer were used to evaluate the reflection loss of double-layered structures using transmission line theory. A reflection loss of less than −10 dB for entire band was obtained for RAS 8 with a total thickness of 3 mm. At central frequencies of 10.6 GHz and 11.0 GHz RAS 6, RAS 3 shown −32 dB and −35 dB, respectively, corresponding to 99% absorption of incident electromagnetic radiation. The proposed double-layered RAS are lightweight promising structures for radar absorption application.

Manganese zinc ferrite nanopowder was prepared by sol–gel auto combustion method. XRD analysis was carried to estimate the crystal structure and average diameter. Hysteresis behavior of the synthesized nanoparticles was studied with VSM. Composite laminates were prepared to study the microwave absorption properties like permittivity, permeability, and reflection loss in X-band frequency. The laminates were fabricated with epoxy as the matrix containing MnZn ferrite as magnetic fillers in different weight percentages using the hand layup method. Complex permittivities and complex permeabilities were measured using a vector network analyzer in the X-band frequency. Reflection loss of multilayered composite structures was estimated using a MATLAB code developed based on transmission line theory. A maximum reflection loss of −25 dB is obtained for a four-layered structure at 10.2 GHz.

This article describes the occurrence of the recent natural fiber hybrid composite mistreatment as strengthening with the hybrid materials using fiber and polyester matrix and polyester resins. The sheets of the composites were made from Ramie fiber with the matrix of Flax fiber and polyester. The resin used was polyester resin. The composite weight division was maintained at 20% fiber and 80% resin. To verify the mechanical characteristics of the natural hybrid composite fiber, the cutting of the specimen is finished within the required shape after the hybrid composites have been made. Thus, fashioned material permitted tensile, flexural, effect and compression tests at entirely in distinct orientations. In order to match experimental outcomes, the finite element inquiry is administered. The conclusions were taken as to the differentiation of the effects of these hybrid composites on the various characteristics of materials.

Al LM13 alloy reinforced with MgO particulates of 0–10wt% in terms of 2wt% were developed by the stir casting technique and the prepared samples were characterized on the basis of microstructure, Brinell hardness, XRD, and SEM. The hardness test indicated increased hardness of the MMC as the MgO particulate percentage increased. Optical microscope studies indicate the MgO particulate distributed randomly in the Al LM13 matrix. The presence of MgO was also identified in XRD. The wear performance of Al-LM13/MgO composite was examined on pin-on-disk equipment. The experimental studies on the MgO particulate increased the wear rate and decreased proportionately indicating the active role of the MgO particulate in reducing the wear. SEM suggests the presence of adhesive and abrasive wear mechanism with evidence of transfer films. The development in the wear resistance is due to the presence of MgO particulates in the Al LM13 matrix alloy.

Propelled materials, for example, constant fiber-fortified artistic grid composites offer huge improvements in an assortment of properties when contrasted with their mass, solid partners, etc. These properties incorporate essentially the ductile pressure, flexural stress, and crack parameters. Anyway to date, there are not really any logical examinations that gave an account of carbon fiber based propelled earthenware composites where SiC is utilized as the lattice. The present work is an endeavor to draw out the flexural fractural quality properties alongside a nitty-gritty examination of the crack conduct of 2D and 3D woven carbon ceaseless fiber strengthened (silicon carbide) ceramic–matrix composite (CFCC) materials. The crack propagation conduct has been dissected in two symmetrical indents and the introduction and its esteem are available in this paper.

The main objective of present study is to see the feasibility of aluminum alloy deposition over mild steel using aluminization technique to improve the corrosion resistance by developing an economically feasible technique. Aluminum alloy coating has been done by dipping the mild steel in hot liquid metal of aluminum alloy at above 800 °C for various time intervals; hot dipped mild steel rods were allowed to air cool. Coatings were characterized to observe the grains diffusion between coating and base metal, it is found that coating metal is diffused into mild steel surface and formed a corrugated grain profile that is facilitating interlocking between both surfaces and this is desired to improve bond strength. Hardness test and toughness test were conducted to observe the strength of the coating and found that coating strength is improved. This process assures a tight bond between the base metal and coating metal.

The interest for lightweight, less expense, and prevalent material required the improvement more up to date materials and consequently an exertion has been taken to create aluminum lattice composites by stir casting technique, which is the easiest and affordable path for delivering aluminum matrix composite. The creation of aluminum matrix composite was finished by strengthening with different weight % of quartz. The result demonstrates that increasing of quartz in aluminum composite increased the hardness and rigidity. The wear test uncovered that expansion of quartz diminished the wear loss and expands the wear resistance. The SEM result on microstructure demonstrates the no throwing imperfection and wear resistance of the composites.

From the last few decades, self-healing techniques came into existence which has wide applications in the aerospace, automobile industries, biomedicine, etc. The polymers have the ability to repair the damages caused by various actions of impact, fatigue, and erosion and restore the original characteristics of material. Its lightweight, good processability, chemical stability, low cost, and high strength make it smart material. Self-healing is inspired by biological study. There are three main concepts of self-healing: capsule-based self-healing mechanism, vascular self-healing mechanism, and intrinsic self-healing mechanism. The aim of this article is to give a complete idea about the application and mechanism of self-healing polymers and its nanocomposites. Impact damages, fatigue, puncture, and corrosion are reviewed by this article. Safer, long-lasting, and economical products can be produced using self-healing polymers. Finally, this article wraps up with great scope in research and developments. Sources of information were from scientific articles, patents, and different materials.

The aim of this experimental study is to determine and compare the fire penetration results of natural fibre reinforced composite material with plywood. Because of their availability, cost, as well as, physical and mechanical properties of natural fibre reinforced composites, they are most widely used in industrial applications like insulating material, building and transportation industries. The application of this composite material needs different properties for different applications, but in case of insulating and building material purposes their thermal properties must be studied, fire penetration rate is one of the important factors in indicating the fire hazard. From this study, it is concluded that fire penetration rate of composite material fabricated by sisal, coconut and palm leaf sheath fibres is less, i.e. 0.206 and time taken for penetration is 87 s that is double the time taken for plywood for penetration.

AA6063 aluminium alloy coating was deposited over IS2062 mild steel using friction surfacing technique and the microstructural evaluation was studied at various process parametric combinations to obtain relationships between the input parameters and grains interlocking which were observed from microstructural evaluation and with microhardness. The microstructural evaluation of the coating images across the interface using microstructure image analyzer and hardness was also measured across the interface using micro Vickers hardness. Studies revealed that no defect along the interface and very good bond integrity between aluminium alloy and mild steel. Coating exhibited fine grain size microstructure along the interface. It is noticed that aluminium alloy layers are cohesive with mild steel and coating layers dovetailed with base metal which is required for interface strength. Mechtrode rotational speed (N), axial load (F) Table speed (Vx) are noteworthy elements and influence the output parameters. Based on the observation of results more metal transfer at the parametric combination of higher axial load and traverse speed with lower rotational speed produced sound coating. Based on various ranges of parameters, combination of strong bond is obtained in a close range of parameters’ combination. Coating metal and base metal are incongruous and have propensity to form brittle inter-metallics

Polymer hybrid composites have superior mechanical composites such that it can be applied for numerous applications. Hybrid polymers composite suggests the design engineer acquires the significant properties in a significant degree by the selection of fibers and matrix. In the present examination, the mechanical properties of coconut fiber and carbon fibers reinforced polyester hybrid composite were investigated. The basic hand lay-up strategy was utilized for the manufacturing of hybrid composites. The mechanical properties, for example, tensile, flexural, and impact strengths of the hybrid composites were assessed according to the ASTM guidelines. Various proportions of the fibers in the composite specimens with random orientation are tested for the mechanical properties. Examination of treated and untreated fibers was additionally considered to know its effect on the mechanical properties. The mechanical properties were enhanced as the carbon fiber content expanded in the composite specimen.

Aircraft wings are slender because of their high aspect ratios resulting from large spans and they are susceptible to vibration problems. Hence, in the design of aircraft wings, frequency analysis is a very important input. In this work dynamic behavior of Boeing 747-400 (having aerofoil number BAC 465) aircraft wing is carried out using finite element analysis. A CAD model of the wing is prepared including aerofoil, the engine attached to the wing and the details of the winglet. Detailed frequency analysis in the range 0–300 Hz of the wing with respect to maximum displacement and von Mises stress is conducted. The results obtained are useful inputs for analyzing resonant frequencies and the design of the wing.

The femur bone happens to not only be the largest bone in the human body but also one that is most susceptible to fracture. In this paper, a study has been made on the structural and vibrational analysis of the femur bone by making use of a finite element solver (FES) in this case ANSYS. The purpose of the work is to gain an insight into the effective design of bio aided equipment. The femur bone is subjected to (free–free) and (fixed–fixed) boundary conditions were for both the cases natural frequency is in the range of 0–1382.5 Hz and 1254.3–8497.3 Hz. The mode shape and the fracture location can be determined and identified. The results are compared with results available in the literature and it was found to be acceptable with a variation of only 1–2%. It was observed that sudden impact repeated vibrations excitation is a major reason for femur bone failure and the results of this study show that the critical failure occurs at bone shaft (the region between two joints) and neck region.

The main aim of this paper is to Design, Analyze, and Fabricate an air intake for CBR 600rr, which is a 4-cylinder engine that is intended to be used in Formula Student Competition. The mass flow rate to the engine has to be fed by a 20 mm restrictor as per rules portrayed by SAE and Formula Bharat. In order to satisfy the rules, a venturi-type restrictor along with a cylindrical shaped plenum with 4 cylindrical runners is included in the design. The restrictor has a converging and diverging angle of 14 and 6 degree, respectively. The main objective is to achieve appropriate velocity at the outlet for proper mixing of fuel with air and minimum pressure drop across the inlet to the throat. The analytical study has also been properly discussed here to make other researchers and students have a clear understanding of the theoretical study on the air intake. It makes use of the Bernoulli theorem and continuity equation to find pressure difference between downstream flow end pipe narrow sections. The design of air intake is done using Solid Works, ICEM CFD is used to generate the mesh to the model where the hybrid mesh is implemented to this model. ANSYS Fluent is used to run the case and simulate. Further to validate our results experimentally, a mass flow rate sensor and a pressure sensor are included. The air intake is fabricated using aluminum as it has the capability to withstand vibrations from the engine and also the suction pressure of the engine.

The use of the optical device for the measurement of surface roughness reduces complexity and time for measurement. In the current study, surface roughness parameters were measured after machining on a shaper machine using the machine vision system which was compared with that obtained through the stylus method. Machining operation involves complexity and produces different surface finish with different cutting conditions, therefore in the present study correlation between surface roughness parameters (viz. arithmetic average height (Ra); maximum height of peaks (Rp); root mean square roughness (Rq); maximum height of the profile (Rt), and ten-point height (Rz)) and optical surface finish parameters (i.e., mean, standard deviation, skewness and kurtosis) has been developed for varied values of cutting parameters (i.e., depth of cut and RPM of pulley drive). The linear relation model with optical parameters and surface roughness parameters has been developed. It was observed that all the roughness parameters can be estimated with a fair degree of accuracy (R2 > 0.92) using optical statistical parameter kurtosis, while means, skewness, and standard deviation obtained through the same image processing data fail to estimate roughness parameters.

The brake pedal is used to actuate the brakes of any normal car. It faces a very high load during intensive and repetitive braking. A brake pedal is required to be durable as well as have a low weight. The study is focused toward designing an optimized brake pedal having good durability and a considerable factor of safety along with the lowest weight. First, the brake pedal of Aluminum (7075 T6) is designed using a 3D modeling software (SolidWorks) and then the Finite Element Analysis is carried out to find the stresses induced when a load of 40 kg, i.e., 392 N acts. Once the results are determined for the solid pedal the pedal is then further optimized by removal of material in less stressed zones and analyzed appropriately.

The paper describes process of design and analysis for the clevis joint. These are widely used as an extreme to steering rack to drive the power of steering rack to the tie rod of the vehicle. This research aims to design the clevis joint for reducing the weight and increase the steering stability of an all-terrain vehicle (ATV), while considering a satisfaction safety factor for both handling and performance of the vehicle. The first step is modeling the clevis joint as per the operational consideration and the various design constraints. The next stage is stress analysis using finite element software and design adjustments for decreasing weight without conceding the structural strength.

Suspension system plays a vital role in Formula SAE’s overall performance as it isolates the vehicle from disturbances and provides a comfortable ride. The motive of this study is concerned with one of the major components of this system; rocker (bellcrank). A solid model of suspension rocker using 3D modeling software Solidworks is prepared and structural analysis is carried out by providing specific boundary conditions. The proposed new optimized model of suspension rocker has less weight and at the same time is competent to perform the function.

Flexibility in manipulators/robots is due to both joint and link flexibility that makes up the system. Flexible robots are preferred over conventional rigid robots in applications like invasive surgeries, space applications, and industries due to their prompt response, low energy requirement, faster operational speeds, and low weight to power ratio. Due to inherent flexibility, accurate positioning of end-effector in required path is difficult. Moreover flexibility of link makes it an infinite degree freedom system and mathematics is very involved. To simplify the problem and get reasonable results, flexible links are modeled based on Euler–Bernoulli beam theory and Assumed mode method is implemented. Joint flexibility is because of small clearances that are inherently present in the joint, because of both manufacturing and assembling constraints, these clearances cause sudden impacts between the joining parts (journal and bearing) resulting in impact force generation as the joints are manipulated. Resulting impact (hertzian contact) forces increase the overall input torque required to manipulate the end-effector according to our wish. This paper’s objective is to build a dynamic model of a two-link RR type planar manipulator with link and joint flexibility, and determine the maximum error of tip position between a robot with/without flexibility, as the end effect or travels in required vertical path with payload. Further, apply orthodox control strategies (PD, PI, and PID) to reduce the error. The end-effector carries a payload equals its links mass. Using MSC Adams and MATLAB softwares, a co-simulation approach is developed. Both the controllers (PI, PID) radically reduced error through several iterations, PID control strategy achieved better results than PI controller and by both approaches, more than 60% of the positional error is reduced.

There are many machines available in the market which recycle plastic waste (plastic bottles), but this machine is for small-scale, portable and domestic purpose. The cost of this machine is very low compared to the machines available outside. This machine is designed to cut the large solid material into small pieces. This paper throws light on the mechanism used in the machine and primarily about the analysis (manual and computational) of the shaft, on which the cutting blades are mounted.

In this paper, an isotropic rectangular plate of finite width with a central circular hole has been considered. Plane stress finite element study under uniaxial, uniformly distributed, constant tensile loading, and temperature gradient has been carried out separately and validated. The combined study has been carried out by maintaining the temperature difference between two sides of the plate. By doing so it has been observed that the maximum stress occurring at the discontinuity getting reduced up to some optimum temperature (the temperature at which von Mises stress getting increased) after that it is crossing the maximum value of stress that had occurred in case of structural stress. As a result, the maximum reduction in SCF obtained is 13%. The optimum temperature value is different for different axial loading values.

In recent years, Composites are rapidly developing and replacing metals or alloys in numerous Engineering applications as automobiles, Marine Engineering, Aerospace, etc. Due to their properties like resistance to wear, corrosion, high stiffness and strength for reduced weight, superior fatigue characteristics, etc. This study, aimed to analyze the fracture toughness of glass fiber epoxy composite by analyzing the specimen in commercial finite element package in ANSYS environment and there by validating it through experiment. For the experimental process, the glass–epoxy composites plate has been fabricated by hand layup process considering epoxy resin as the matrix and woven roving as the reinforcement. The composite specimens are tested by performing a SENB (single edge notch bend) test to study the fracture toughness and the crack propagation of the glass fiber epoxy composite. The comparison showed good agreement.

Automatic gate system makes a property more secure and exclusive. In today’s era of automation, it is not just an advanced electronic feature to have an automatic gate but more often a need to provide high-end security. In this paper, an automatic gate system is designed which uses an autofocus camera to automatically recognize the license plate of a vehicle along with the vehicle type and model. The system uses Raspberry Pi 3B + and other sensors along with Node-RED for connecting the processor and different devices to form an Internet of Things (IoT) network. The use of autofocus infrared camera enables accurate recognition of vehicle license plates even with broken or distorted license plates. It also helps in detecting fake license plates with proper programming. Node-RED connects all the devices together by facilitating the flow of data from different sensors to the Raspberry Pi processor and also the uploading of data to an online database. This automatic gate system is easy to set up and has extremely useful features with robust body for unpredictable weather conditions. With the use of Raspberry Pi 3B + the processing is fast and execution is quicker with on-chip Wi-Fi module.

The overall objectives of the investigation are to decide the journal bearing lubrication features, for example, pressure distribution and oil film thickness. These trademarks can be uncovered by settling the condition that administers the fluid–structure connection happening amongst journal bearing. The pressure distribution of the greasing up oil is controlled by unravelling Navier–Stokes condition; the energy condition gives speed plots, which one used to get the pressure distribution plots by illuminating pressure Poissons condition. The pressure distribution got from Navier–Stokes is utilised to discover the power and removal by settling the anxieties and relations. The weight profile of greasing up oil is fixed consider CASTOR oil as lubricating oil for different length–diameter ratios of the journal bearing by keeping the constant eccentricity value. The overall objectives of the investigation are to decide the journal bearing grease qualities, for example, weight conveyance and oil film thickness. These attributes can be discovered by settling the condition that oversees the fluid–structure cooperation happening between journal bearings. The analysis is also carried out for material like bronze for different length–diameter ratios and constant eccentricity value to find the displacement, stress and pressure profile distribution in the bearing structure by using the boundary condition. For analysis, it is accepted that the flow is laminar and steady and the fluid used for analysis in CFD is CASTOR oil and the boundary condition used is speed 3000 rpm. From this, the result will be the pressure profile for journal bearing. The pressure profile for the CASTOR oil after analysis is found to be as 58092.15, 58212.35, 59162.68 and 59592.64 N/m2.

Dealing with increased levels of vibrations and annoying noise is a major task in front of today’s automotive industry. Uncontrolled vibrations lead to the damage of the vehicle systems. The impact due to large force transmissions introduces large values of unbalanced forces and eventually large stress values. Computational tools are indeed beneficial in resolving the issues through modeling and simulation. Advanced design techniques uses different software and programming methods to evaluate the problems at design stages itself. Harmonic analysis is very critical in the design stages as well as in the operative stages. The unevenness on roads, like speed breakers cause excessive vibrations and uncontrolled dynamics in a vehicle. This paper illustrates the harmonic determination for a vehicle through modal analysis. Modal analysis enhances the capability in determining the modes of vibrations along with frequencies at which these modes occur. The results from modal analysis are compared with the measured values from FFT analyzer. Results from these efforts are discussed, which shows the effectiveness of modal analysis and vibration measurement. Significant reduction in failures of vehicles on roads due to excessive deflections at high vibrating frequencies is a major task. This paper contributes in addressing the issues related to analyzing the vibration levels of vehicle chassis on road surface conditions.

In most of the applications of vibration compared to the elastic and inertia forces, the magnitude of damping forces is small. Under certain circumstances, these small forces may, however, create great influence. Damping is one of the important parameters in the study of dynamic systems. It is generally measured under conditions of cyclic motion and is defined as the energy dissipation in a mechanical system whose free oscillations decrease with time, resulting in a decrease in its amplitude of vibration. From a theoretical point of view, there are two different methods to measure damping, i.e., time response methods and frequency response methods. In rotating machinery, the measurement of damping by applying time response methods and frequency response methods is very difficult. Due to that reason, there is a lack of experiments to measure damping in rotating machinery. This paper discussed Kelvin–Voigt approach for measuring damping in mechanical systems. The mechanical system analyzed in this thesis is a rotating shaft. In general, damping can be explicit through different parameters as damping ratio (ζ) or loss factor (η). Therefore, the objective about this paper is to determine one of these parameters by means of measuring simple variables such as forces or displacements.

Harmony Search Algorithms (HSA) is one of new meta-heuristic technique use in optimizing the parallel machine scheduling. HSA has gained much popularity in solving identical parallel machine scheduling problems such as minimizing the maximum makespan time. In HSA, a permutation-based improvisation process implemented in solving different optimization issues in the identical parallel machine scheduling. The HSA has proposed due to various characteristic advantages such as it is efficient, simple, easy and accurate. In this paper has been discussed various researcher’s HSA application in identical parallel machine scheduling and summarized their conclusions.

Type III and IV shock interactions on the scramjet cowl principal edge produces localized heating of surfaces and leads to thermo-structural failure. One of the methods to protect these surfaces is by blowing shock away with supersonic injection of coolant into stagnation region. The displacement of shock depends on the mass flux ratio of supersonic jet and free stream of projected area. The strength and type of shock interference depends on the location of shock generator. Computational analysis carried out to evaluate the effectiveness of this method with the above parameters. The contours of flow field presented. Shock standoff distance and effective heat flux reduction computed. Geometry and structured grid generated using ICEM CFD. The simulations carried with ANSYS CFX. It found that the minimum shock standoff distance to protect the structure is with mass flow ratio of 0.34. Computed shock standoff distances for the mass flux ratios of zero, 0.17, 0.34, and 0.51 are 4, 8, 12, and 19 mm respectively. The standoff distances are successive integer multiples of zero mass flux standoff distance.

The intention of this research is to obtain an ideal suited arrangement of hybrid electricity generation system using various renewable energy sources to meet the village load prerequisite reliably, economically, endlessly, and sustainably. Hybrid system consists of sun energy, wind power, and conventional electric generator. The analysis is done in the year 2017–2018 at Deleta Village in Meta Robi District, Oromia region, Ethiopia for hybrid electrification. The required solar potential values and wind speed statistics were taken from NASA. The data shows that the study site has an average wind speed of 2.9 m/s at 10 m anemometer and solar radiation of $$5.81\;{\text{kWh}}/{\text{m}}^{2} /{\text{day}}$$. The cost of associated hybrid components is collected from various springs and the electric load data was estimated for community and public service’s needs. HOMER software was used to perform techno-economic assessment to meet the load requirement using renewable hybrid off-grid configuration. Based on the resources, load, hybrid system, and the component cost input data were considered. The simulation in HOMER gives optimization, sensitivity, and grid comparison results. The optimization result of the simulation demonstrates that the hybrid configuration achieves total NPC of $1,506,689 and COE of 0.360 $/kWh at a renewable fraction of 0.6 as the best optimal hybrid configuration considering economic and environmental point of view. From environmental standpoint of view, the system is characterized with a minimum percentage of carbon dioxide and other GHG emissions of about 195,974 kg/year.

The Off-grid renewable power generation system cannot provide an efficient and continuous supply of electricity without a storage medium. Consequently, batteries are added to the hybrid system. In order to ensure the continuity of power supply without severe stress on the battery bank for a reduced overall cost, a conventional generator is also incorporated. After selecting the appropriate components and studying their characteristics, a hybrid system that consists of PV/wind/diesel generator/battery is demonstrated in HOMER using the estimated electrical load, renewable energy potential, and the costs of the hybrid system components. Then, the simulation is made to determine the best optimal hybrid configuration system that can supply the village load with the required level of availability.

In various fields of engineering, optimization plays a key role in the development of new technology. In this wake, this paper discusses in detail, the concept of optimization, a few advanced methods and approaches most commonly used in different applications optimization process. The two most popular optimization procedures are also contrasted and discussed.