Recent Advances in Mechanical Engineering, Volume 1

Vibration control is swiftly advancing in research, with diverse techniques being investigated to minimize detrimental vibration levels. Compared to metallic alloys, composite materials offer superior material properties while being lightweight. The main objective of this study is to develop active control techniques on Carbon/Glass Epoxy-reinforced composite sandwich beams with viscoelastic core using Proportional Integral Derivative (PID), Linear Quadratic Regulator (LQR), and Linear Quadratic Gaussian (LQG) Controllers. The approach involves conducting an experiment to obtain the Transient Response of the beams subjected to free vibration, which is then utilized to obtain the Transfer Function and State Space variables. MATLAB-Simulink obtained transfer function is used for implementing controllers to actively attenuate vibrational amplitudes and settling time. The outcomes reveal a significant reduction in settling time and vibrational peak amplitudes.

Machining is emerging with a scorching potential to produce the tiniest to most complicated geometrical shapes. This study examines how cutting velocity (CV), depth of cut (DOC), feed per tooth (FPT), coolant flow rate (CFR), nozzle tool distance (NTD), and nozzle elevation angle (NEA) affect MQL face milling of the substrate with titanium nitride-coated carbide inserts. To establish a mathematical model and recognize the significant process factors of these process parameters, several machining experiments based on 3-factor and 3-level factorial experiment designs were completed (L27) with ANOVA tool. The models revealed a correlation between cutting parameters and material removal rate (MRR). The insert geometry, which incorporates a scraping edge, allows for a higher material removal rate even at the critical depth of cut, followed by coolant flow. Optimal process parameters increase MRR by 236%. MVLR second-order empirical model with R2 adjusted of 0.935. Additionally, a mathematical model grounded in empirical data is built to verify material removal rate estimates that would significantly enhance the application of aluminium alloy substrate.

Electrical discharge machining is emerging with a scorching potential to produce the tiniest to most complicated geometrical shapes in aerospace, automotive, biomedical, and marine applications in today's industrialized world. In the automotive industry, HSLA steel offers a fantastic opportunity to reduce weight while maintaining strength. The primary applications for HSLA steel include oil pipelines, construction equipment, and road vehicles. With copper and graphite electrodes, the authors, therefore, seek to explore the surface roughness (SR) of high-strength low alloy (HSLA) steel during high-precision machining. To test the output response SR, the input parameters pulse on time, current, and duty factor is chosen. Surface roughness of 0.64 and 0.81 µm is attained for copper-HSLA steel and graphite-HSLA steel, respectively, with 100 µs pulse on time, 4 A current, and 80% duty factor. Additionally, a mathematical model grounded in empirical data is built to verify surface roughness estimates.

Geopolymer is a novel form of concrete with the exclusion of cement completely. It is produced from the reaction of aluminosilicate material and alkaline activators. The commonly adopted methods of curing geopolymer concrete are oven curing, ambient curing, steam curing. It has been discovered that oven curing provides higher mechanical strength. However, oven curing method is limited to precast structures, in other to develop a geopolymer concrete which will be able to set at ambient condition, small amount of calcium-rich material can be used like slag, eggshell powder (ESP). For this research, ESP is used together with metakaolin due to it richness in calcium which responsible for setting of concrete in OPC, its availability, and the threat it poses to the environment due to improper disposal. The alkaline activators bind the unreacted materials together and produce sodium aluminosilicate hydrate (NASH), the major compound for strength development. However, in oven cured method, higher molarity of sodium hydroxide results into higher compressive strength, there is reduction is strength when there is excess sodium in the mix which can react with CO2 present in the atmosphere and lead to carbonation which can lead to deterioration of the concrete. Metakaolin is replaced by 0, 10, 20 and 30% ESP. It was discovered that ESP has a substantial effect on the mechanical and durability performance at ambient temperature at 14 M, and there is reduction of strength at 16 M.

“The Sustainable Development Goals (SDGs)” came into existence with the aim to mitigate the various socio-economic and environmental issues. The sustainable use of the energy resources is one of the goals of the 17 SDGs. The world is facing energy crisis due to the limited access of non-renewable sources of energy. The Renewable Energy Source (RES) can help us in overcoming the problems of energy needs. The Goal 7, i.e. “Affordable and Clean Energy” includes the target of proper utilization, use of advanced techniques and to increase the share of RES. The selection of the type of RES is a major concern especially in developing countries. To solve this problem, many techniques are used like “Multi-Criteria Decision-Making (MCDM)”. “The Hesitant Fuzzy Linguistic Term Set (HFLTS)” is used to remove vagueness and uncertainty in the results obtained by the various MCDM techniques. A “Hybrid Fuzzy Python MCDM model” is developed here for the selection of best RES in India. The “HFL Analytical Hierarchy Process (AHP)” is used to weight the criteria and sub-criteria which are identified with the expertized suggestions and then rankings of the alternatives are obtained by the HFL TOPSIS. The calculation for the whole hybrid model done with the help of Python programing. To check the applicability of the described model, a practical application aided by expert assessments has been provided. This research study find novelty in a way that such model has been used for the first time. The hybrid fuzzy model can yield different results using other MCDM techniques and taking other criteria.

Unmanned aerial vehicles, commonly known as drones, serve a wide array of purposes, including aerial photography, mapping, surveillance, package delivery, agriculture, and search and rescue missions. Operators now need to make more deliveries as a result of the explosive expansion of online ordering. To fill this demand, drone-based technologies are employed. This main goal is to describe the layout and assembly of a quadrotor drone that can deliver objects. These drones can move goods between locations, including food, supplies, and medical equipment. The top and lower plates, as well as the arms, are made using 3D printing technology. Using the Pixhawk 2.4.8 flight controller to operate the drone and send the delivery to the selected location. The drone can operate autonomously in autonomous mode with GPS and Mission Planner software to command and plan the mission. SolidWorks software is used for 3D modelling of quadrotor drones.

The performance and reliability of electronic systems have been seriously affected by the heating density of semiconductors. The enhancement of the heat transfer improves the thermal rating, and life of the component and also saves energy. A detailed investigation was carried out to investigate the thermos-hydrodynamic properties of a fluid in a microchannel operating under laminar flow regime. The numerical simulations were carried out at different flow rates, and geometrical parameters at constant heat flux 900,000 W/m2 for a range of Reynolds numbers 100 to 400. The obtained results were validated with experimental results and parametric analysis done with different grooves like continuous, bottom, side, and rotating grooves and sine wavy channels of the amplitude of 0.1 and 0.2. The bottom grooves offer less obstruction among all grooved channels and wavy channels. The maximum Nusselt number observed is 10.74 at Reynolds number 400 in connected grooves and the maximum friction factor noticed is 0.391 in sine wavy channel amplitude of 0.2 at Reynolds number 400. The connected grooves gave good results compared to all other cases, with a maximum increase in performance of 60% more than the straight channel at Re = 400.

Tuned mass dampers (TMDs) are effective devices for increasing structural damping in various applications. This study proposes a new design of TMD using fused deposition modeling (FDM) in additive manufacturing (AM), which favors for customizable parameters such as stiffness and mass with minimal changes during manufacturing. This design approach can reduce the number of components required for manufacturing and assembly. The paper focuses on investigating the damping mechanism and performance of the additive-manufactured TMDs for a low-frequency experimental setup. A simulation approach is developed to predict the effects of the TMD in reducing transient vibration time. Several TMDs with different tuning parameters are fabricated using polyethylene terephthalate glycol with the FDM method. The TMDs are tested on a beam and verified through simulations, and the design is adjusted to suit different conditions. The results demonstrate the effectiveness of using FDM in AM to design TMDs with customizable parameters. The designed TMDs reduce the transient vibration time by 39% along with reduction in part count by around 90%, and the proposed approach can potentially lead to the development of more efficient and cost-effective designs as it reduces the part count to two. This study provides insights into the damping mechanism and performance of additive-manufactured TMDs and presents a solution for improving structural damping in various applications.

Ultrasonic non-destructive testing (NDT) requires the involvement of an expert operator for inspection and interpretation. This makes the process outcome sensitive to multiple forms of human error, leading to inaccuracy in results. The present demands of society have increased the volume of inspection and testing costs exponentially. The potential solution to these problems is to use machine learning (ML), and recently researchers and industries have started exploring the diversity of ML techniques to use in NDT. This paper investigates the prospect of the artificial neural network (ANN) to characterize the defect in NDT through simulation and experiment. First, synthetic A-scan data was generated from an angle beam ultrasonic model using COMSOL, and using these data the depth of the defect was characterized using a feed-forward neural network. It is found that a simple topology of 10:10:2 network performs well and gives a correlation coefficient of 0.95 between the output and target. Second, an experiment was performed by preparing samples (mild steel blocks) with artificial defects at different depths. The depth characterization was performed by extracting the features from A-scan data using a phased array ultrasonic testing (PAUT) device. The result shows that the feed-forward network can predict the depth of defect with a mean squared error of 0.0701.

The present work aims to investigate the effects of the abrasive water jet machining (AWJM) process on the surface quality of green composites (GC) through an experimental investigation and parametric analysis. Experiments are conducted-based Taguchi (L27) OA by varying AMGS, SoD, NS, AMFR & WP, and the corresponding responses like surface quality (Ra) are measured. Thereafter, effect of process parameters and most optimal combinations for AWJM process is identified through parametric and ANOVA. Furthermore, utilizing liner regression analysis, a mathematical model is created for the best Ra prediction for the AWJM procedure. In order to validate with the experimental findings, the confirmatory analysis has finally been tested. According to the results, Ra is significantly influenced by the parameters, namely AMGS, AMFR, SoD, and NS. The ideal setting for AWJM process is obtained as AMFR as 2 g/s, WP as 80MPa, SoD as 2.5 mm, NS as 200 mm/min, and AMGS as 40 mesh.

This paper discusses the experimental investigations to comprehend the role of nano titanium dioxide (nTiO2) and nano molybdenum disulfide (nMoS2) dispersions in two types of biodegradable oils. Before machining, the nanofluids are formulated at 4% from 0.25 to 1% to test basic properties, namely thermal conductivity and absorbance. These tests are followed by machining at fixed cutting conditions through minimal quantity lubrication technique at 20 ml/min using 0.25% nanoparticle dispersions in base fluids. Cutting forces and temperatures are quantified online, while surface roughness and tool wear are noted offline. The machining performance of nanofluids is compared with dry, conventional oil (SAE oil), pure coconut, and canola oils. It is observed that nanofluid formulations refined machining results compared to other lubricant environments. 0.25% nTiO2 in coconut oil resulted in bringing down temperatures, forces, surface coarseness, and tool run out by 60% compared to dry machining, 35% better than SAE oil, 25% better than pure oils, and 15% better than nMoS2-based cutting fluids, respectively, on an average.

Military vehicles mostly operate on rough roads, and hence, stability and ride comfort is of paramount importance. This mine protected vehicle (MPV) is used by military for anti-insurgency operations in disturbed and unsafe areas which involves patrolling and recce 24 × 7 through uneven roads connecting villages. Hence, ride comfort to keep troops vibrant and fiery all the time and vehicle stability in the event of fire on move is utmost important. Ride analysis of three-axle MPV over rough terrain is not seen reported in literature, and hence, this study is an important contribution. This study focuses on analysing and modelling three-axle military vehicle suspension response using rough roads akin to military terrain generated as per the guidelines stated in ISO 8608 and minimizing vertical acceleration keeping in view the road holding parameter. The ride comfort is a measure of root mean square (r.m.s) acceleration at centre of gravity in vertical direction. Road holding is determined by the ability of a vehicle to stay in contact with road under all circumstances, especially while negotiating bump, braking, accelerating, and cornering. Power spectral densities of vertical displacement at reference spatial frequency are used to generate an artificial road profile of varying degree of roughness using MATLAB and serves as an input to Simulink model. The equations of motion are derived using Newton’s second law of motion for three-axle vehicle, and further passive suspension model is created using Simulink. The same is been validated using MATLAB code (ODE-45 solver) with same parameters. The response so obtained from passive model involves high vertical acceleration beyond permissible limits as mentioned in ISO 2631–1. Further obtaining optimum value of damping coefficient considering road holding and acceleration. The model is then incorporated with PID controller in an attempt to bring acceleration well within permissible limits of passenger comfort. Present model with parameters as derived provides better ride comfort and road holding with 14.30% reduction in r.m.s acceleration of sprung mass in vertical direction.

Armour steel is commonly used in armoured vehicles, military equipment, and structural components that require high resistance to penetration. Cutting armour steel poses several challenges due to its exceptional strength and hardness. Overcoming these difficulties in armour steel cutting requires the use of advanced cutting technologies, specialized tools, and careful process planning. The present research paper focused on an experimental study of wire electrical discharge machining (WEDM) process variables and multi-objective optimization to achieve the optimal cutting rate (CR) and surface roughness (SR) for armour steel. This study has been carried out using the fractional factorial method, with peak current (C), pulse on time (A), wire feed (E), spark voltage (D), and pulse off time (B) as machining parameters and workpiece thickness (F) as a material parameter. The main effect plot, interaction plot, and ANOVA have been used to analyse the effect of the input parameters on the response parameters, followed by developing regression modelling. The results of the study demonstrated that the Ton and workpiece thickness have the major contributions to CR and SR, respectively, with 55.25% and 21.77% contribution for CR, and 67.87% and 8.72% contribution for SR. A2B1C2D1E2F1 and A1B2C1D2E1F2 are the optimal set of input parameters for CR (0.71 [mm/min]) and SR (2.46 [microns]), respectively. The study employed the desirability function approach (DFA) for multi-objective optimization, and the results indicated that the composite desirability for CR and SR is 0.6414. The combination of 1.1 µs Ton and 38 µs Toff, 140 A I, 20 V V, 10 m/min WF, and 146.97 mm workpiece thickness is the optimum set of input parameters.

The purpose of this research is to enhance the microstructure and mechanical characteristics of powder coating on grade V Ti-6Al-4 V alloy using tungsten inert gas (TIG) cladding with various rare earth metals (RE). Ti-6Al-4 V alloy is a widely used material in various industries. The coating was produced by blending powders including grade V titanium alloy (Ti-6Al-4 V), tungsten carbides (WC), aluminum nitrate (ALN), nickel (Ni), and different rare earth metal oxides (CeO2 and La2O3) in a fixed ratio and then applied to the surface of Ti-6Al-4 V alloy using TIG cladding. Variable currents (300A, 400A, 500A, and 85A) of various samples were used to examine the microstructure and mechanical characteristics of coatings. The observation of the result showed that the microstructure and grains of the samples depend upon different rare earth metal oxides as well as varying currents. A refined columnar grain microstructure was formed for all the samples containing RE’s oxides, and short columnar grains and microneedle-type appearances were formed without RE’s oxides. Due to varying currents, the uniform distribution of fine columnar grains had a hexagonal structure, and equiaxed grains were formed that enhanced the mechanical characteristics of titanium alloy such that the sample has a microhardness between 500 and 870 HV0.5 with RE oxides and 368 HV0.5 without RE oxides.

Traditionally, conventional fuels such as LPG, kerosene, biomass, and wood have always been used for mass cooking in places such as temples, hotels, and other community centers such as hostels and orphanages. As such, there has been a huge strain on the ever-depleting sources of energy such as fossil fuels and wood, not to forget the pollution and emission of greenhouse gases caused by these fuels. These issues can be tackled using completely green and environment-friendly methods of community cooking. In this paper, one such method of green energy, i.e., “Concentrating solar energy” will be discussed. Parabolic dishes that focus light can produce high temperatures ranging from 350–4000 ℃, which makes them ideal for cooking large quantities of food. Advanced solar steam cooking systems are capable of feeding anywhere from 50 to 25,000 people on a consistent basis. This paper will take up case studies for a few of these mega kitchens, viz. Temple of Shirdi, BrahmaKumaris region of Mount Abu. A proper economic analysis will be presented for these community cooking setups, in which their cost savings and effectiveness against traditional fuels like LPG will be shown.

Metal matrix composites are widely recognized for their notable enhancements in wear resistance compared to polymer matrix composites. But the low weight, easy manufacturability, low melting points, and comparable mechanical, electrical, and thermal properties of polymer matrix composites make favorable for using in different loading and environmental conditions. This research article is focused on wear properties of polymer and polymer composites obtained using COMSOL Multiphysics software under different loads. The key objective is to examine how polymers and polymer composites wear on pins and von Mises stress distributions inside the cylindrical pin. The study aims to evaluate the material combinations based on the amount of polymer wear, which is mostly affected by measurable wear on the polymeric component. However, it is noted that certain material combinations may result in significant wear to the counter face. The study also highlights that the polymer specimen's weight loss may not be a reliable predictor of polymer wear. Therefore, the American Standard Test Method (ASTM-F732) has been established as the benchmark for evaluating candidate materials intended for use as bearing surfaces in human total joint prostheses. This standard offers a laboratory procedure specifically designed to analyze the wear characteristics of material mixtures under consideration.

The over-dependence on fossil fuel in IC engines has brought it to the verge of extinction. It also releases harmful pollutants into the atmosphere after combustion. This study aimed to simulate and analyse the functioning metrics of a diesel engine under different fuel blends to determine their impact on engine performance. The simulations used a 60-degree sector meshed geometry model with closed-cycle simulation. The simulations used different fuel blends, including D100, chemically similar to diesel fuel, and four other fuel blends containing varying percentages of ethanol and methanol. The objective was to identify the best gasoline blend in terms of emissions, fuel consumption, and engine performance. The simulation results for D100 showed a thermal efficiency of 38.16%, CO emissions of 0.571 g/kg-f, and EINOx of 176 g/Kg-fuel. The fuel mixture (D80E20) with 80% diesel and 20% ethanol was the best suited for engine emissions and performance according to the results for the other fuel mixes. The D80E20 blend had a thermal efficiency of 47.38%, in-cylinder pressure of 79.99 bar, temperature of 1896.70 K, indicated power of 10.49 KW, EINOx of 6g/Kg-fuel, and ISFC of 183.55 g/KW-h. Due to its lower emission value compared to D100 and the other five mixes, D80E20 has a greater thermal efficiency. High oxygen concentration in the fuel blend helps achieve complete combustion, which, in turn, leads to a decrease in unburned hydrocarbons and particulate matter, ultimately resulting in lower emissions.

Harvesting energy from vibrations is an alluring source for small-scale devices like batteries and small sensors. Vibration-based energy harvesting is a technique to scavenge energy from environmental vibrations. In this paper, Macro Fiber Composite (MFC) patch adhered to the cantilever beams is used for harvesting energy. The major objective of this paper is to increase the relative displacement of the tip of the cantilever beam with respect to its support so as to maximize the amount of energy to be harvested. An experimental setup is designed and fabricated to harvest vibrational energy in a wide range of frequency source. The setup is designed in such a way that the natural frequencies can be varied and a desired natural frequency can be tuned to the excitation frequency so as to increase the amplitude of oscillations of the cantilever beams. It uses magnets and the application of an increasing axial force on the simply supported beam so that multiple variations of the configurations can be tested, by imposing and superimposing the different forces acting on the cantilever beams, thus helping to navigate how the setup will perform under different circumstances. The use of Macro Fiber Composites in piezoelectric harvesting offers advantages such as improved mechanical properties, flexibility, and scalability compared to traditional piezoelectric materials. The experiments are conducted on two sets of cantilever beams, one with the MFC patch adhered to it, and the other set is to analyze the effect of different system parameters on the relative displacement amplitude of oscillations of the cantilever beams. The relative displacement amplitude of a cantilever beam is further increased by a set of attracting magnets, thus creating a bistable condition for the cantilever beam.

In this article, the Radial point interpolation method (RPIM) and Element free galerkin method (EFGM) are used to model fracture problems by introducing the intrinsic basis functions to obtain the Stress Intensity Factor (SIF). The study has been conducted to compare the accuracy of SIF and the computational cost by enriching the nodes and background mesh. The problem is solved for different values of crack size to width ratio. The SIF comparison is done to edge and center crack problems for 4 different cases (1) without enrichment, (2) with just background mesh refinement, (3) with just nodal refinement and (4) with background mesh and nodal refinement. Based on the study, comparative table of different cases is presented along with the error analysis based on the analytical SIF values.

Multi-directional machines offer benefits over traditional designs when it comes to maneuverability in crowded environments. Mecanum wheel systems operate by applying rotational force to each wheel individually, enabling them to move freely in a different direction. This allows for straightforward movement, although not for rapid maneuvers. The key advantage of employing mecanum wheel systems is the separation of translational and rotational movements, which facilitates uncomplicated stirring, but not swift stirring. Therefore, the present work is undertaken to study the forklifts using mecanum wheel. An attempt is made to design and perform structural analysis of the forklift using ANSYS. The analysis is made for lifting 101 kg of weight on its base frame and 22.5 kg for wheel rim. Additionally, the design calculations for motor shaft and power consumption are determined. After analyzing parameters such as stresses, total deformation, and factor of safety, it is determined that both the base frame and wheel rim have a factor of safety greater than 1. This indicates that the structure can withstand higher loads while experiencing minimal deformation and maximum equivalent stress.

This work focuses on producing TiC-GO coating on AISI 52100 steel to improve the tribological properties by Electrophoretic deposition (EPD) method. The parameters of this study are applied voltage, coating deposition time, composite solution concentration, and sintering temperature. Optimization of different combinations of TiC and GO is primarily found out and the best TiC-GO combination is selected by considering the least tribological response. In the next stage, the EPD parameters for the best are optimized by using the Taguchi L16 method. Microscopic and elemental analysis is done to confirm the presence of uniform composite coating (TiC-GO) on the surface of the substrate. The results revealed that the COF of the optimized combination of TiC-GO is 0.155 for a sliding distance of 350 m, which is very near to the predicted COF. The wear loss for the optimum combinations is also less compared to that of pure substrate.

Environmental sustainability can be achieved by fuel derived from biological origin. Many authors concluded the safe use of a lesser blend of biofuel with diesel in the engine is not sufficient to decrease the dependency on diesel. High content of biodiesel has higher viscosity which is one of the major hurdles in replacing the B20 blend and diesel as primary fuel in internal combustion engines. Preheating of fuel is a proven technique to improve the fuel properties of biofuels. The performance improvement of the Compression Ignition engine was explored by preheating the higher blends of PME (Pongamia Methyl Ester) biodiesel blends using a Waste Heat Recovery Heat Exchanger. Biodiesel blend B60 (60% biodiesel and 40% diesel) of PME is preheated from 60 to 110 °C using exhaust gas heat, and its performance characteristics are compared with the B20 blend without preheating. Combustion improved due to an increase in peak in-cylinder pressure and heat release. The thermal efficiency improved by 17.83% compared to the B20 blend. Also, the CO, HC, and Smoke were reduced by 50%, 66%, and 62% respectively compared B20 blend at 75% load and 110 °C preheating.

The current investigation delved into the exergoeconomics of a combined cycle gas turbine system, employing the exergy costing method followed by 1st law analysis. Through exergy analysis, the study facilitated the determination of the exergy destruction rate across all components, subsystems, and the entire plant. Assigning a cost function to each exergy stream enabled the calculation of both the entire plant cost and the cost related with exergy destruction. Key operational factors for analyzing thermodynamic and cost-related performance included compression ratio, turbine inlet temperature, and the degree of inlet air cooling. The latter increases with ambient temperature, while the compressor inlet temperature remains constant at 288 K. Simulations were conducted to explore the effects of these variations and other input parameters. Notably, the combustion chamber emerged with the maximum cost rate of irreversibilities. Moreover, the cost rate of both exergy destruction and topping cycle work production increased with the degree of inlet air cooling. Importantly, the latter escalated at a more rapid pace, establishing the advantages of inlet air cooling from both thermodynamic and economic perspectives. Taking into account total capital cost and destruction cost, the study suggests greater pressure ratios (≥14) and lower turbine inlet temperatures. However, in scenarios with a high electricity price per unit, justifying increased capital investment for a combined cycle power plant with high turbine inlet temperature becomes reasonable.

This study examines the performance of a dual evaporator ejector system and contrasts it with a traditional dual evaporator cycle employing a pressure-reducing valve. The cycles have been compared for the same cooling capacity in low-temperature evaporators and unit flow rates of R152a, R134a, and R1234yf refrigerants. The system was validated, and results were numerically simulated using Engineering Equation Solver (EES). The effects of varying the evaporator and condenser temperature have been analyzed in the present study. It is found that compressor work decreases in the ejector-assisted cycle; thus, the total exergy increases in the exergy analysis while increasing the condenser temperature. The study found that the ejector-assisted dual evaporator cycle had a 14.6–18.78% reduction in total exergy destruction when compared to the conventional dual evaporator cycle with a pressure-reducing valve. The R134a of an ejector cycle provides 13.57–15.65% COP improvement and 12.46–14.69% exergy efficiency improvement respectively over the conventional cycle. The COP is found to be maximum for MDEEC using R152a as refrigerant.

The usage of additive manufacturing (AM) as a production technology for end-use products has increased due to advancements in the field. It permits the production of more complex parts with least waste material at a relatively low cost. Recent advancement in the domain is additive manufacturing of fibre reinforced polymer (FRP) materials having high strength to weight ratio. However, the mechanical properties of additively manufactured components depend upon the process parameters. This paper presents the correlation study of Fused Deposition Modelling (FDM) process parameters with mechanical properties of additively manufactured Nylon-Carbon fibre composite material. Infill density, layer thickness and infill orientation were the process parameters considered based on their influence on the strength of the component. Tensile strength, compressive strength and impact strength were considered as the response parameters. Tensile specimens were fabricated as per ASTM D638- Type I standard, while compressive and impact test specimen were fabricated as per ASTM D695 and ASTM D256 standards respectively. A fractional factorial Taguchi orthogonal array- L9 (3 parameters, 3 levels) was developed, and the influence of the process parameters was evaluated using Taguchi analysis. Based on the parametric study, the result showed that the infill density prominently influenced the strength of the component. Inverse proportionality was observed between the layer thickness and tensile & compressive strength, whereas impact strength exhibited direct proportionality with the layer thickness. Furthermore, tensile and compressive strength increased when the infill orientation was aligned with the loading direction, while impact strength increased with cross-oriented infill.

In the current paper, novel microchannels heat sink (MCHS) with ribs and filleted rib corner designs are investigated numerically. Microchannel with square ribs (MC-SQ), MCHS with square ribs and corner with fillets (MC-SQ-FR), and MCHS with square ribs and corner with double fillet (MC-SQ-DFR) are the three designs that are considered. CFD package Ansys Fluent was used to accomplish 3-D numerical solution. Thermohydraulic performance of this configuration is assessed by analyzing their Nusselt numbers, pressure drop, base temperature, etc. According to the findings, the fillet of the rib corner significantly raises the thermal performance while just slightly raising the pressure drop. In comparison to MC-SQ, MC-SQ-FR improves the Nusselt number by 15–22% and raises the pressure drop by 2–10%, respectively. Additionally, the MC-SQ-FR configuration outperformed all others due to the redevelopment of the thermal boundary layer and increased mixing level.

In numerous industrial applications, high-performance micromixers find extensive usage, particularly in processes where mixing at low Reynolds numbers and within the laminar regime is crucial. To enhance mixing efficiency, the physical principle of chaotic advection is often employed. This study is numerically investigating the helical spiral passive-micromixer (HSTM), with fast mixing at low axial length with the help of chaotic advection. Characteristic of flow ‘mixing index’ results compared with the helical spiral micromixer. Blood is the working fluid that has the rheological characteristic of non-Newtonian fluids. HSTM gave a higher mixing efficiency of 98.5% at a low blood flow rate, i.e., 0.00004 kg/hrs and 79.5% at ṁ = 0.014 kg/hrs. Also, we have analyzed pressure drops of the HSTM to anticipate the energy demands necessary to propel the fluid. Thus, HSTM has a wide application in fields like biochemistry and biomedical.

In this paper, TiO2 and Fe3O4 nanoparticles (NPs) are infused in magnetorheological fluid and blended in different proportions. This paper aims to find out the magnetorheological fluid with better properties by infusing nanoparticles which makes it dynamic and worthy for variety of applications. Hence the effect of blending of TiO2 and Fe3O4 nanoparticles is studied on magnetorheological fluid properties. The percent of TiO2 and Fe3O4 added in magnetorheological fluid in different weight percentage finalized from research papers. TiO2 percentage is kept constant at 0.2%. Fe3O4 is added viz; 0.5, 1, and 1.5%. For the prepared sample, density is measured and sedimentation rate is calculated after the observation of prepared samples for 80 h. Shear stress, viscosity and magnetic flux density values were measured by using rheometer. In the experimentation, it is found that density is slightly increased due to the weight of iron particles. Out of the prepared blends, S2 i.e. 0.2% TiO2 + 1% Fe3O4 in magnetorheological fluid combination is found with increased viscosity, increased Shear stress and decreased sedimentation rate which is a better option for various magnetorheological applications.

Additive manufacturing, or AM, or 3D printing is the technology that is commonly used to create genuine three-dimensional objects that made of ceramic, metal, polymer, or combination of these materials. Currently, AM routes are attracting different fields of applications because of its lightweight and significant mechanical strength. The friendly user interface of fused deposition modelling (FDM) increased much attention amongst the different AM techniques. In the recent trends, it has transformed the rapid manufacturing of polymer-based customized composite parts. Therefore, in the present work, PLA (polylactic acid)-based carbon nanofibre composites structures were manufactured using FDM-based 3D printing technique. Further, experimentations were performed by designing two different pore architectures such as rhombus and octagon and subsequently evaluate its performance by varying the strut thickness under uniaxial compression testing. The strut thickness was varied between the ranges of $$1\; {\text{and}}\; 1.5\;{\text{mm}}.$$ 1 and 1.5 mm . The results shown that octagon structures were exhibited better mechanical strength as compared to rhombus structure. Moreover, the different mechanical properties such as Young’s modulus, maximum compressive strength, and compressive yield strength were increased with an increase in strut thickness of pore design in the range of (237.5 to 477 MPa), (7.55 to 23 MPa), and (6.5 to 13.5 MPa), respectively.

Passive cooling systems have become crucial because of the damaging effects of traditional air conditioning systems on the environment and their excessive energy consumption. An effective passive cooling system uses a GCHE (ground-coupled heat exchanger) to use the earth as a heat sink or source. The GCHE would use around 76.5% less energy to produce the same level of cooling on a normal summer day than traditional air conditioning systems. The soil temperature is significantly lower compared to the surrounding air in summer, and conventional GCHEs are deeply embedded in the soil. They are typically difficult to install and maintain as a result of their deep burial. The GCHE, a near-surface with short-grass ground cover, is one alternative, where there is sufficient temperature difference at very low depths only. The current study examines the impact of outlet temperature on parameters like inlet airflow rate, intake air temperature, the thermal conductivity of soil, pipe material, tube thickness, and pipe diameter. The varied thermal conductivity soils from France, Ajmer, and Jodhpur have been taken, and all of their parameters have been compared with the results of the current study.

This research work made an effort to produce A356–Al2O3–B4C composites. The composites were fabricated via stir casting process with various weight percentages. The compositions of the composites are A356, A356-5wt.% Al2O3-5wt.% B4C, A356-10wt.% Al2O3-5wt.% B4C and A356-15wt.% Al2O3-5wt.%B4C composite. The scanning electron microscope (SEM) was used to examine the microstructure on the produced composites. SEM microstructure shows the fine dispersal of Al2O3 and B4C with matrix. The effect of Al2O3 and B4C weight percentage on density, porosity and corrosion behavior was investigated. The results revealed that addition of Al2O3 and B4C reinforcement increases the density and corrosion resistance and reduces the porosity. Mechanical properties of the reinforced A356 composites with various weight percentages were evaluated as per the ASTM standards. Assimilation of Al2O3–B4C composites with different percentages of weight enhanced hardness, ultimate tensile strength of A356.

Ultrasonic waveguide techniques are most familiar to monitor fluid level, viscosity, corrosion, and temperature for hostile environments. The potential advantage of using waveguides is to monitor various condition monitoring applications because the transducer could be placed outside the hostile or in-access areas. And also, a single waveguide could be used as multiple sensors by incorporating echogenic features (notches) in appropriate lengths. Here, stainless steel strip waveguide comprising reflectors at appropriate gauge length was fabricated to monitor temperatures at multiple locations. A shear wave transducer (0.5 MHz) was used in the pulse-echo technique to propagate S0 wave mode in the strip waveguide. Reference reflections from the notches are considered as time of flight (TOF) which could be collected at various temperature instances. The strip waveguide sensor and the co-located thermocouples are calibrated using the resulting time-of-flight shift (δTOF) from the reflectors. A machine learning model was used to extract a best-fit calibration equation with a heating cycles. The obtained calibration equation can be used to extract the temperatures at various spots on the structure where the waveguide sensor is placed. The developed single strip waveguide sensor, designed for measuring temperature at multiple locations, is easy to use, durable, and affordable. It is suitable to tracking the temperatures in the hostile and difficult to access areas.

The analysis of the mechanical properties of ice composites encompasses three key aspects: material novelty, fiber selection, and strategic placement within the ice matrix. Controlled experiments were conducted using four different materials: rice husk, sawdust, waste paper, and glass fiber. Ice composites were fabricated with a 10% wt. fraction of each material and frozen at −20 ℃ for approximately 24 h. Flexural and fracture toughness tests were performed using a three-point bend using a universal testing machine (UTM) to evaluate the mechanical properties. Reinforcement led to significant improvements in flexural modulus and strength, with waste paper achieving approximately 90 and 1082.5% improvements, respectively, and glass fiber achieving approximately 166.37 and 968% improvements, respectively. However, fracture toughness results showed that glass fiber outperformed waste paper with an approximately 837.77% improvement compared to 188.8% identified experimental errors that were summarized, and corresponding improvement plans were proposed.

The latest green welding technology, friction stir welding (FSW), was believed to manufacture exceptional welds with minimal defects. It is evident that the amount and type of defects determine the performance and the application of any weldment fabricated using any welding technique. The world of artificial intelligence is setting its footprints in almost every research domain. This work focuses on the implementation of the machine learning concept for classifying defective and non-defective weldments using an unsupervised learning technique called anomaly detection. Subsurface defects of weldments were captured on the films using conventional radiography testing. The developed semi-supervised generative adversarial network model built for the classification turned out to be a robust model for classifying the defective and non-defective radiographic images. This developed model for detecting anomalies in radiography weld images may be utilized in a various industrial applications where digital radiography is used to examine welds, such as the aerospace and automobile sectors. The model may be used to automate the identification of anomalies in radiography images, resulting in a faster, more accurate, and less prone to human error inspection process. It may also be used to spot defects that human inspectors may overlook, resulting in better safety and reliability of the inspected structures.

An experimental study on a greenhouse solar dryer (GHSD) with a floor area of 1.82 × 1.52 m2 was conducted to dry handmade papers. The performance of GHSD was investigated under no-load and load conditions, and variation in drying time was compared with that of shade drying. Operating parameters like temperature and relative humidity (RH) of air outside and inside the dryer, solar intensity, weight of handmade papers dried in the shade and in the dryer, etc., have been recorded and analyzed during the experimentation. Handmade papers (75 in number) of 100 GSM (grams per square meter) thickness with a moisture content of 60.8% (w.b.) were dehydrated to 9.6% (w.b.) in 2.5–3 h inside the greenhouse solar dryer while traditionally drying, i.e., shade drying the same number of papers took 17–18 h. The maximum air temperature inside the dryer under no-load and load conditions was recorded to be 49.4 °C and 49.2 °C at solar intensity of 556 W/m2 and 594 W/m2, respectively, on the day of experimentation. The acquired findings demonstrate the variation of temperature, RH, relative humidity, moisture content, and drying rate, indicating that the developed dryer performed satisfactorily.

This work focuses on analyzing tensile and flexural characteristics of jute/glass fiber/epoxy hybrid composite filled with charcoal. Various composite samples were prepared by manual method of composite fabrication with 2–2 layers of glass fibers and jute fiber and three different percentages of charcoal powder, viz. 1, 2, and 3 wt%. The outcome of tensile test and flexural test was evaluated, and it was found that the charcoal addition resulted in positive enhancement in tensile properties as well flexural properties. Maximum tensile stress is obtained for 2 wt% of charcoal incorporation with tensile strength of 98.77. MPa. The maximum bending stress was observed for 2 wt% of charcoal sample with bending strength of 1856.44 MPa.

It is very challenging for amputees to walk and adapt to uneven surfaces. It is essential to classify different gait surfaces so that intelligent prostheses can be designed for automatic gait adjustment. In this study, supervised machine learning algorithms are used for the gait classification of uneven surfaces. Gait pattern plays a significant role in human movement. Inertia measuring unit (IMU) sensor data is used, which is mounted on the right shank body part. Acceleration data in the x-direction is used for the gait classification of uneven surfaces. Nine different surfaces, namely data slope down, slope up, stair down, stair up, bank right, bank left, cobble stone, grass, and flat even, are studied. Fourteen features, namely mean, RMS, kurtosis, standard deviation, crest factor, skewness, shape indicator, clearance indicator, min, impulse indicator, range, max, margin factor, and energy, are extracted from the data. Supervised machine learning algorithms namely K-Nearest Neighbour (KNN), support vector machine (SVM), Ensemble classifier and Neural network (NN) are employed for gait classification. A maximum gait classification accuracy of 87% is obtained for the subspace discriminant ensemble classifier.

This article aims to study the effects of changes in internal radial clearance, number of balls and rotor speed on the vibration responses of a balanced rotor-bearing system. This rotor-bearing system is modeled and simulated using FEA software ‘COMSOL Multiphysics’. The rotor-bearing system consists of a rotor shaft and rigid disk, which are supported by two SKF 6205 bearings. Three levels of each factor are considered, i.e., three radial clearances: 1, 27 and 53 μm, three ball numbers: 6, 9 and 12 and three rotor speeds: 2800, 6500 and 10200 rpm. The mean displacement (MEANZ) and RMS velocity (RMSVZ) of the inner race center (IRC) in vertical direction (Z-direction) are used as output vibration responses. Full factorial design (FFD) and analysis of variance (ANOVA) are used for design of experiments and their analysis, respectively. Regression equations are prepared, and various plots are plotted using Design Expert software. The results show that MEANZ increases considerably with increase in radial clearance; however, it decreases slightly with increase in number of balls. But, MEANZ is not affected by the change in rotor speed. Also, the RMSVZ increases significantly with increase in radial clearance, increases slightly with rotor speed, and decreases with increase in the ball numbers. This study will enable vibration diagnostic experts to grasp the impact of three factors that lead to vibrations in the rotor-bearing system.

The present investigation focused on the study of gas holdup, RPM and heat transfer coefficient in a bubble column. The investigated bubble column (ID 0.2 m and height 1.8 m) was assembled with a pressure swing rotating bubble cap (PSRBC) sparger, which is capable of producing bubbles with self-rotation simultaneously. The gas holdup, RPM and heat transfer studies were carried out in stationary water with compressed air in the present bubble column as the distribution of the gas phase was more uniform than the existing bubble columns. The sparger was a cylindrical shape of 0.01 m in diameter and 0.12 m in height with 18 angular nozzles fixed in three layers on the lateral surface of the cap. The column was operated with the supply of compressed air (through a helical copper pipe inside the water bath) to the static liquid column of various heights with the help of a PSRBC sparger. The influence of superficial air velocity on gas holdup, RPM and heat transfer coefficient has been studied. Model equations have been developed for predicting gas holdup, RPM and coefficient of heat transfer for the PSRBC sparger bubble column in the present range of investigation. A comparative analysis of Stanton number between stationary and rotating PSRBC sparger has been done. The heat transfer coefficient was enhanced in the latter one. The findings of the present investigation may help industrial applications like deaerator and gas–liquid interacting systems, where the gas phase is supplied to the liquid through a bubbling manner.

This research primarily analyzes heat transfer inside a double-pane window of an electric bus. Phase-change material (PCM) is filled between two glasses to investigate its effect on heat transfer by conducting a numerical simulation on a commercial software of ANSYS-Fluent. 3-D transient heat conduction and solidification-melting model considering enthalpy-porosity approach have been solved in glass and PCM to obtain the temperature distribution. The main objective of this work is to reduce the energy consumption of the batteries used for air conditioning by storing the energy in a phase-change material. A solar heat flux on the glass window is set to 800 W/m2. Then the absorbed heat is conducted through the external glass (on the ambient side), PCM, and internal glass (on the cabin side) before entering the bus cabin. The PCM layer and glass thickness are considered to be 14 mm and 5 mm, respectively. Convective heat transfer takes place from the internal glass surface to the bus cabin with a convective heat transfer coefficient of 9 W/m2-K. The simulation for this problem was carried out for 5 h (18,000 s). The average surface temperature and liquid fraction at various times were noted and plotted for a thorough discussion. A substantial temperature reduction of about 5.73% was achieved using PCM.

A quadruped robot is an underactuated system. In the case of underactuated systems, the degree of freedom of the system is less than that of the actuators provided for the motion. So, the body movement needs to be controlled indirectly by defining proper trajectory, gait, and contact parameters. In this paper, the quadruped robot is modeled using design software, and the complete robot is specified using a unified robot description format. The body movement of the quadruped depends on the foot trajectory and the gait pattern to be implemented. This paper defines a mixed gait pattern to study its impact on body motion. The gait defined combines the advantages of trot and static gait. D-H convention is used to define the axis for joints. Simulations are carried out in MATLAB–Simulink. Kinematic equations are designed for the leg system and the body of the quadruped. Kinematic analysis is used to generate joint-space trajectories from task-space trajectories. The inverse kinematic solver available in the Robotics System Toolbox creates joint-space trajectories. Simulations are performed using these joint-space trajectories. The simulations are performed to observe the body motion. The plot of the body’s translation and rotation concerning time suggests that the gait has been executed with stable body movement. The iterative simulation defines contact parameter values to perform a stable gait with stable body movement.

This paper is focused on the investigation of a polymer–metal composite radio frequency absorber applications used for airborne, submarines, EMI shielding, etc. Nickel (Ni) metal powders having mesh size of 100 and 325 are used as fillers and finely dispersed in the millable polyurethane (m-PU) matrix to prepare flexible absorber sheets, using solvent casting process. The filler volume fraction is varied from 20 to 40 in the m-PU matrix to find the optimal filler loading based on density as 30 and 35 vol%. The samples are characterized by X-ray diffraction (XRD) to ascertain phase stability and scanning electron microscopy (SEM) for microstructure analysis, and tensile test is performed to determine mechanical properties and Fourier transform infrared (FTIR) for elemental composition analysis. The electrical permittivity, magnetic permeability and their losses are ascertained using vector network analyzer at the K- and Ku-band (12–27 GHz) to analyze the absorption.

In this paper, the effectiveness of virtual simulation laboratories in creating conceptual comprehension of heat transfer techniques is investigated. One of the concepts in thermal physics that the students frequently find challenging is understanding heat transfer mechanisms. The efficacy of using virtual simulation laboratories for teaching the three heat transfer processes—convection, conduction, and radiation, is each assessed. The findings of this study demonstrate how virtual laboratories’ integration of sensory and physical representations aids in learners’ overall comprehension of the subject matter. An investigation of understanding for N = 86 mechanical engineering students revealed that using the heat transfer experimental virtual laboratories (HTEVL) performed significantly better than those students not using HTEVL, on comprehension tests, taking noticeably less time to complete and increased total scores. The perspective of heat transfer experiment comprehension as being difficult was also decreased, according to this study. The level of learning enhancement based on distinct attributes of HTEVL was quantified by statistical tests on the various assessment methods conducted both online and in the traditional laboratory. There is a discernible difference between the two student groups’ responses in this study’s results. The control group has mean test scores that were relatively low as compared with the experimental group. It may be also stated that the learning simulations created in the form of HTEVL can depict the heat transfer process effectively.

Minimizing compression set in industrial rubber products such as O-rings, seals, and gaskets is one of the most desirable features. Nitrile rubber (NBR) is an oil-resistant polar rubber which is intentionally selected as the matrix to mix with polar lignin to reduce the time for preparation. In this study, a hybrid mixture of carbon black and lignin is incorporated as filler in the rubber matrix. The NBR–lignin–carbon black composite is prepared by dry rubber compounding in a laboratory internal mixer. The maximum filler loading is limited to 30 parts per hundred rubber (phr), and the composite is tested for various mechanical properties by varying the amount of lignin and carbon black. The curing time obtained for lignin-filled samples is within the acceptable limits of the rubber industry. The minimum value of the compression set is obtained at a loading of 25 phr of lignin in the hybrid mixture. Furthermore, the inclusion of lignin did not reduce the mechanical properties such as hardness and tensile strength considerably. Morphological study shows good dispersion of lignin in the rubber matrix up to 25 phr of loading. Replacement of carbon black with lignin through industrially viable dry rubber compounding is a significant observation that points out to scalability and sustainability.

Solar air heater (SAH) is a simple device for harnessing the solar power for heating air. The introduction of various fins, grooves, etc. on the absorbing plate increases the effectiveness of the SAH. The numerical analysis for achieving the effective performance of a SAH is studied in the current work. Semicircular grooves of 30 mm diameter are introduced in the wavy absorber plate of the SAH. The amplitude and wavelength of the wavy-shaped absorber plate are 17.19 mm and 137.5 mm, respectively. Along with the thermo-hydraulic characteristics of the SAH, the temperature and the velocity variation have been analyzed for varying Re between 3500 and 16,000. For the steady state 2-D flow study, a continuous heat flux of 1000 W/m2 is provided to the upper portion of the absorber plate, and the analysis is carried out in ANSYS FLUENT 23.0. The highest THPF is obtained to be 1.87 when the Re is 16,000. The introduction of semicircular grooves on the wavy absorber plate leads to better performance than the conventional SAH.

Aircraft stalling and spinning are major causes of aviation accidents and fatalities; hence, using slots in airfoils is essential for lowering that risk. There has not been much research on the geometrical dependence of flow features around an airfoil, despite previous studies concentrating on fixed-wing slots. Applications in aircraft wings, wind turbine blades, watercraft, and unmanned aerial vehicles (UAV) demand an understanding of how slots affect airfoils. Using a NACA 4412 airfoil, which is frequently used in the aerospace industry for small-scale transonic flight, this study attempts to examine the effects of a rectangular slot close to the trailing edge. The airfoils with and without slots are compared, taking into account an inflow Mach number of 0.9 and an angle of attack of 0°, 10°, and 16°, respectively. This gives a thorough grasp of the performance characteristics of the airfoil at various angles of attack. The flow around the airfoil was simulated using ANSYS Fluent, a pressure-based solver, and the SST k-omega turbulence model. The production of vortices and their movement towardthe upper surface of the airfoil, followed by the movement of high-pressure air from the lower surface of the airfoil, can be caused by a slot close to the trailing edge. The aerodynamic effectiveness and stability of the airfoil can be considerably impacted by these vortices. The results show that the slot delays flow separation, resulting in a decrease in drag and an increase in lift, particularly at higher angles of attack. Additionally, as the span lengthens, the airfoil's stability grows. The vortices created by the slot can create attached flow and lessen drag by lowering turbulence close to the airfoil's wake. The study emphasizes the solver's aptitude for resolving pressure waves, vortices, and other flow characteristics within and around the airfoil.

UNS S32750 is a SDSS (super duplex stainless steel) grade, and it is widely used in gas industry and petrochemical processing plant due to its remarkable combination of mechanical characteristics and corrosion resistance. It contains a substantial quantity of chromium, which results in solid solution strengthening and better corrosion resistance. Even in chloride and sulfur-rich conditions, this alloy shows resistance to severe destructive corrosion forms like pitting. Welding is the typical manufacturing technique employed to fabricate components for industrial utilization. Due to changes in microstructure in distinct zones of a weld, the welding process influences both mechanical characteristics and corrosion resistance. An effort has been made in the current study to evaluate the influence of MMA, GTA welding processes on UNSS32750 alloy by analyzing microstructural changes during welding and developing an understanding of the pitting corrosion. Microstructural analysis for weld zone (WZ), heat affected zone (HAZ), and base metal in a weldment were conducted using scanning electron microscopy and optical microscopy. The weld zone microstructure exhibits Widmanstatten structure in the GTA welds. Superior properties of GTA welds were observed in the present study with optimum combination of fine microstructural characteristics and corrosion resistance. The slower cooling rate associated with GTA welding, which results in increased austenite formation and a more balanced ferrite-to-austenite ratio, may account for the enhanced characteristics compared to MMA welding, as rate of cooling is the crucial factor that influences the corrosion behavior of these welds.

Vortex shedding has been very less investigated and applied phenomenon in the field of fluid mechanics. Apart from tall slender column structures, subsea pipelines, and submarines, it has a lot of capability for many other applications like flowmeters, heat exchangers, etc. Vortex shedding has also been recognized as a potential generator of energy harnessing renewable resources like wind, water, etc. The energy/signals produced is highly influenced by periodic pressure fluctuations in the wake region of the bluff body. This current research work is focused on simulating two-dimensional vortex shedding of external flow over a ribbed and grooved cylinder using computational fluid dynamics (CFD). Ribbed and grooved cylindrical structures are the common structures in the engineering field. This study aims to evaluate the coefficients of drag and lift as well as vortex shedding frequency for the flow past a circular cylinder with Grooves and Ribs on the surface. The cylinder with six grooves and six ribs each at an angle of 60 degree, respectively, are compared with respect to their external flow analysis of vortex shedding. The results show that the lift and drag coefficients of grooved cylinder increased significantly as compared to regular cylinder whereas the vortex shedding frequency remained nearly the same. However, it is found that the configuration of circular cylinder with ribs showcases a significant reduction in vortex shedding frequency up to half as compared to regular cylinder, whereas the lift and drag coefficients are increased by small amounts. From the results obtained, it is suggested that for applications of structural stability in the presence of external flow cylinder with ribs are preferable whereas for energy/signals production cylinder with grooves are preferable.

Flat heat pipes (FHPs) are employed in various industries and applications where efficient heat transfer is required to maintain the operation and reliability of the system such as electronics cooling, aerospace, medical devices, etc. The impact of the shape of flat heat pipes (FHPs) on the effective thermal conductivity of FHP has been experimentally investigated in the present work. The copper-based FHPs were charged with DI water, and a single layer of 100 mesh screen was employed as a wick structure. The FHP was 0.2 m in length, 0.01 m in width, and 0.003 m thick. The four different geometries such as horizontal, L-shaped (3 different orientations), stair-step-shaped, and U-shaped of FHPs were considered. The FHPs’ functioning was evaluated in terms of effective thermal conductivity at different heat levels for fan-assisted forced convection and free convection condenser cooling. The shape and orientation of the FHP affect its thermal behavior in addition to physical and operational qualities. Among all testing runs, the L-shaped FHP with gravity-assisted (condenser at top and in vertical plane and evaporator at bottom and in horizontal plane) configuration at 12-W heat load and free convection condenser cooling achieved the optimum effective thermal conductivity of 9756 W/mK. Comparing all other shapes, the thermal operation of the L-shaped FHP with this configuration was found best for both fan-aided forced convection and free convection condenser cooling.

This research focuses on the passive modification of aerofoil surfaces to improve aerodynamic performance, particularly the reducing drag. The work is inspired by the drag-reducing properties of shark skin's tooth-like denticles. Simulation-based investigations were conducted to study the effects of incorporating novel denticle-inspired designs along one or both sides of an aerofoil. The objective is to analyse the impact of these denticle configurations on drag and lift. Using ANSYS Workbench, numerical simulations were performed on a 3D aerofoil model covered with shark skin inspired denticles. The simulations aimed to evaluate the aerodynamic performance of the aerofoil with denticle modifications. The focus was on assessing the effects on drag reduction and lift enhancement. The results of the simulations provide insights into the benefits of integrating denticle-inspired designs on aerofoil surfaces. By mimicking the drag-reducing characteristics of shark skin denticles, the modified aerofoil exhibited reduced drag and improved aerodynamic efficiency. The interaction between denticle geometry and flow characteristics was also investigated to understand the underlying mechanisms driving these effects. The findings demonstrate the potential of denticle-inspired surface modifications for enhancing aerofoil performance. The study highlights the importance of denticle geometry, such as size, spacing, and arrangement, in optimizing aerodynamic improvements. Furthermore, the simulation-based approach proves to be a cost-effective and efficient method for evaluating the effectiveness of denticle designs in drag reduction and aerodynamic enhancement. This research contributes to the field of passive control methods for reducing drag and improving aerodynamic performance. The insights gained from this study can be applied in various engineering applications. Further research can explore the practical implementation and optimization of denticle-inspired designs on aerofoil surfaces, expanding their potential impact in the field of aerodynamics.

The hip joint is pivotal in providing structural stability and enabling dynamic lower limbs and upper body movement. Being a ball-and-socket joint, it facilitates various movements, such as flexion, extension, abduction, adduction, and rotation, which are crucial for everyday activities, sports, and leisure. However, the hip joint might experience failure owing to various underlying factors, necessitating a total hip replacement. An ideal material for hip implant should be biocompatible, wear-resistant, corrosion-resistant, fatigue-resistant, and osteoconductive. Various materials have been used for hip implants, including metals, ceramics, polymers, and composites, each with their advantages and limitations. Some of these materials tend to fail the implants and reduce their functional life due to limitations such as cytotoxicity, corrosion, wear and rapid degradation. This requires a revision surgery that places an individual under physical and financial burden. The present article systematically explores the diverse facets of hip implants and their materials. Emphasis is laid on the significance of using Ti-based materials for implants, considering their unique properties. A thorough discussion is also presented pertaining to superelasticity, a unique property that a few Ti-based alloys possess. The paper also reviews the importance of studying different loads acting on a hip implant for pre-clinical assessment of its performance.

The efficient utilization of thermal energy storage (TES) systems depends significantly on the choice of phase change materials (PCMs) and the employed heat transfer mechanism. PCMs used in TES systems often exhibit poor heat transfer rates due to their low thermal conductivity. Improving the heat transfer rate between the heat transfer fluid (HTF) and PCM is crufigcial to capture a larger amount of energy during the PCM's phase change. When PCMs with low thermal conductivity are selected, it becomes essential to enhance their performance. Various research studies have focused on improving the thermal conductivity of PCMs, including the implementation of different fin geometries. Fins can enhance the heat transfer rate between the HTF and PCM, thereby reducing the melting time of the PCM. T-shaped fins have been considered as a feasible option for analysis in computational fluid dynamics (CFD) studies due to their reliability, cost-effectiveness, and ease of fabrication. The present study employed ANSYS FLUENT CFD software to numerically examine the improvement of thermal performance in a shell-and-tube heat exchanger (STHX) through the utilization of T-shaped fins. These novel fin shapes were suggested to improve the melting rate of the phase change material (PCM) within STHX. The thermal performance of the T-shaped fin was compared to that of the traditional longitudinal fin shape, considering the same dimensions and PCM material. The analysis included two types of heat exchangers: one equipped with four longitudinal fins and the other with six T-shaped fins. Three-dimensional numerical models were created, considering the simulation of the melting process and accounting for time variations.

The focus of recent efforts has been on transforming biowaste products, which have no value, into valuable applications, particularly the production of pure carbon from widely available sources such as rice husk. This study aimed to produce pure carbon from rice husk using different chemical activation methods, including single chemical activation methods (HCL, KOH) and double chemical activation methods (HCL-KOH and HCL-H2SO4). The results showed that 1 and 2% purity carbon was obtained using HCL and KOH chemical activation methods, respectively, while 3 and 4% purity carbon was achieved using HCL-KOH and HCL-H2SO4, respectively. Therefore, it was found that the HCL-KOH activation method is the most effective approach to obtain higher purity carbon. XRD, EDAX, and FTIR characterization studies were conducted to identify the crystalline and elemental composition of the extracted carbon, while SEM was used to analyze its microstructure. The results indicate that microporous and mesoporous structures were clearly visible in the extracted carbon produced by both single and double chemical activation methods, as compared to the pure rice husk.

Phosphate-based glass has indeed emerged as a highly promising and versatile material in the realm of biomedicine. Its chemical composition closely mimics the mineral phase found in bones, making it an exceptional candidate for a wide array of biomedical applications. Notably, the glass's ability to closely mimic bone structure facilitates the seamless replacement of targeted tissues in vivo, enhancing the overall effectiveness of regenerative processes. Beyond applications in bone-related treatments, phosphate-based glass fibers exhibit remarkable potential in addressing soft tissue needs, particularly in the realms of ligament and muscle regeneration. The exceptional properties of phosphate-based glass, including controllable degradation, ion release profiles, and compatibility with cells, render it highly suitable for implant applications. Significantly, these unique properties negate the necessity for secondary surgeries to remove the implant, streamlining the overall medical intervention process. This comprehensive review aims to provide an in-depth understanding of Phosphate-based glass, encompassing its chemical composition, diverse properties, various fabrication methods, and biological responses within the biomedical field. Through this exploration, the goal is to underscore the substantial promise of phosphate-based glass and its pivotal role in advancing biomedical field.