Showing papers in "International Journal of Vehicle Structures & Systems in 2022"

Performance Enhancement of Solar Air Heater using Graphene/Cerium Oxide and Graphene-Black Paint Coating on Roughened Absorber Plate

Abstract: A coating on the roughened absorber surface of a solar air heater can improve its efficacy. This paper presents the results of a comparative study of nanomaterial and hybrid nanomaterial coatings on the roughened absorber surface to improve the performance of a solar air heater. The solar heater is designed to assess heat transfer rate, thermal efficiency, exergy efficiency and entropy production. To improve heat absorption, roughened absorber plates were covered with graphene and graphene/cerium oxide -black paint doped into black paint in the quantity of 1% nanomaterial. For constant air mass flow rates of 0.019 kg/s, the results are displayed. When the solar intensity is between 700 and 1250 W/m2, the thermal and exergy efficiency of the graphene/cerium oxide -black paint coating on the SAH roughened absorber plate is 3.36 % and 0.54 % respectively, greater than that of a graphene-black paint coating. For graphene-black paint, entropy generation is larger, whereas for1 % graphene/cerium oxide -black paint, it is lower.

Performance Comparison of Solar Air Heater with Extended Surfaces and Iron Filling

Abstract: The thermal performance of a solar air heater (SAH) is enhanced by producing air turbulence. The air turbulence is created by using either extended surface or iron filing between the black colour absorber plate and glass of the SAH. In this article, the thermal performance of a SAH in the case of without fins and with fins at a different location is compared with the SAH using an iron filling. The value of the overall heat loss coefficient in the case of iron filling is 2.1 W/m2K. The average thermal efficiency of the iron filling condition is 65.14%. The additional arrangement to increase the heat transfer also increases the pressure drop which leads to higher power consumption. Results show the thermal efficiency of SAH using iron filling is found best followed by fin arrangement above, below the absorber plate, and without fin.

Experimental Investigation of Friction and Wear Behavior of AL7075-TiO2-B4C using RSM, ANN and Desirability Function

Abstract: Metal Matrix Composites (MMC) are widely used in high strength and light weight applications. AL7075 featuring high fatigue strength, good corrosion and wear resistance makes it to employ as a good vehicle building material and also finds it usage in some important engine components which are subjected to constant wear. In this study, dry sliding wear behaviour of hybrid MMC formed by reinforcement of aluminium 7075 with B4C and TiO2 at 3% and 3% weight fraction respectively is investigated. Reinforced particles are powdered using ball mill, reduced to nano size and uniformly dispersed in aluminium matrix using stir casting method. Specimen was prepared according to ASTM standards and wear tests were conducted. Experiments were conducted with keeping force, speed and distance as input parameters while Coefficient of Friction (CoF) and average wear rate as the output parameters. RSM and ANN models were developed to simulate the experiments. The surface which was subjected to test evidenced that presence of TiO2 and B4C particles protected the material to a certain extent. The tests revealed that wear rate and CoF were greatly influenced by force and distance followed by the speed of the rotating disc. The predictions from RSM and ANN models are also correlated well with the experimental data. ANN model also showed better accuracy and capability for predicting the wear rate and CoF. By desirability function, it was found that the material performed well at a keeping force of 38.9 N, speed of 300rpm and distance of 1000 rpm.

Thermal Performance Enhancement of CuO-Paraffin Nano-Enhanced Phase Change Material

Abstract: The current work is focused on the synthesis and characterisation of CuO (copper oxide) nanoparticles and investigating the thermal conductivity of CuO nanofluids. CuO was prepared using a wet chemical approach. Newly prepared nanofluid passes through tests to explore its industrial and other applications. An X-Ray diffraction pattern was used to find the average crystalline size of CuO nanofluids. The scanning electron microscope and transmission electron microscope were used to find the morphology, particle shape and size. Dynamic Light Scattering (DLS) was used to find the agglomerated size of nanofluids. The optical properties of the CuO nanofluids were evaluated using ultraviolet-visible absorption spectra. The KD2 pro thermal property analyser was used to find the thermal conductivity of CuO nanofluids and it was discovered that as particle loading rises, thermal conductivity also increases. The performance enhancement of Nanoparticle-Enhanced Phase Change Material (NEPCM) samples was analysed using FTIR, TGA and DSC techniques. FTIR result shows that the physical contact of copper oxide and paraffin does not influence the chemical structure and stability of the NEPCM samples. TGA result shows that as the CuO percentage increases, it enhances the physical bonding interaction between PW and the nanoparticle and improves the stability of NEPCM samples. DSC analysis shows that CuO reduced the impact of super-cooling during the melting and solidification stages. The nano CuO was used to speed up crystallisation and decrease the super cooling effect of paraffin wax. Further, CuO successfully stabilised the heated surface's temperature fluctuation during melting and solidification.

Specific Fuel Consumption and Exhaust Emission Test on Single Cylinder Four-Stroke Diesel Engine using Polyethylene Extract Biodiesel as Fuel

Abstract: More than 70% of the plastic wastes come out the packing materials. This causes heart problems and cancer too in the later stages. The plastics started to blend in drinking water in a major percentage. Recycling of the existing waste plastic is the only major way so that we can reduce this harmfulness to the globe. Here we have made use of polythene which plays a part of 33.5 percentage of the total plastic waste and is the highest waste among them. These wastes are mechanically separated and converted to plastic oil through pyrolysis. These oils are blended with the existing diesel in about 6 to 12 percentage for conversion to biodiesel and tested on a single cylinder four-stroke diesel engine for its performance. The exhaust gas which comes out is tested for its emissions and compared with diesel specific fuel consumption (SFC) and emissions.

Hardness and Impact Strength Characteristics of Al based Hybrid Composite FSW Joints

Abstract: Aluminium and its alloys have an excellent mechanical property in that metal matrix composite has a promising role in the field of automobile and aviation. This work aims to investigate the hardness and impact strength of aluminium Al2024, Al6061 and Al7075 alloy reinforced with a weight fraction of fine greenish silicon carbide 7% and chopped E-glass fiber 3%. The metal matrix composite plates were welded by using the friction stir welding process at 550, 850 and 1150 rpm with a feed rate of 40, 80, 120 mm/min. Hardness specimens are prepared as per ASTM-E-92 and investigated the hardness of welded and unwelded (base metals and composite metal) in nugget zone, HAZ and TMAZ with the help of Vickers hardness test machine. Impact strength specimens are prepared as per ASTM-E-23. The results were compared with welded and unwelded aluminium specimens.

Friction Stir Welding of Dissimilar Aluminium Alloys for Vehicle Structures

Abstract: Welding process in vehicle structures has gained importance, especially for better strength and mechanical properties. Hence, there is vast research going on in the domain of newer welding techniques. Friction Stir Welding (FSW) is one of them. FSW is used in this research to join two different grades of aluminium alloys by varying the process parameters. The process parameters are optimized based on the Design of Experiments (DoE) and the Taguchi techniques. From the experimental findings for different process parameters, the optimized set of conditions involving the normal, transverse forces and the torque are determined. Further, the process methodology is validated.

Synthesis, Microstructure and Wear Analysis of Copper Alloy with Alumina and Graphene as Reinforcement

Abstract: Hybrid copper alloy composites are widely used in numerous industrial applications, such as aeronautics and automobile, because of their wear resistance and excellent cast ability. They are widely used for high load and low speed application such as stone crushers and earth movers. The pin-on-disc dry sliding wear investigation and microstructure characterization of copper alloy reinforced with Al2O3 and graphene particulates were conducted. Stir casting technique is used to prepare the composites. Wear loss of hybrid composite (Cu alloy + 4wt.% Gr + 4wt.% Al2O3) is compared with Cu alloy, Cu alloy + 4wt.% Gr and Cu alloy + 4wt.% Al2O3. In microstructural analysis SEM and EDS images were assessed to know the distribution uniformness of reinforcement in copper alloy matrix. Dry wear test was carried on pin on disc machine. In the first trial, the sliding speed was kept as constant to 300 rpm and load was varied in range of 1 kg, 2 kg and 3 kg. In the second trial, the load was kept as constant and the sliding speed was varied in range of 100, 200 and 300 rpm. Results in both trials have shown that the wear resistance was increased and wear rate was very low in hybrid composite (Cu alloy + 4wt.% Gr + 4wt.% Al2O3) compared to the other compositions of the tested composites.

Design and Parametric Study of Counter-Rotating Propeller of Unmanned Aerial Vehicles for High-Payload Applications based on CFD-MRF Approach

Abstract: The compact Unmanned Aerial Vehicles (UAVs) implementation in real-time applications is emerging everywhere because of its compact size, high accuracy, etc. But in the case of high payload based applications mini UAVs are unfit to execute the mission due to the increment in the propeller's dimensions to overcome high payload. To overcome such increment in geometry of a mini UAV for high payload issue, the co-axial propeller based propulsive system is the best alternate, which can be able to provide high thrust with compact size and more stability. Therefore, the study about co-axial propeller and its performance has emerged. Similarly, this work also deals with the comparative investigation about the cumulative thrust force effect on co-axial propeller. Aerodynamic force calculation on the co-axial propeller is executed with the help of standard aerodynamic formulae for validation purposes. The conceptual design of the co-axial propeller is modelled in CATIA. Numerical estimation of aerodynamic forces on UAV's co-axial propeller is analysed with the help of ANSYS Fluent. After the drag comparison, the distances between the propellers in the co-axial set-up are modified for optimization. Finally, the different models undergone comparative numerical simulation and thereby optimization took place.

Design and Analysis of Control Strategy for an Efficient Battery Thermal Management System of an Electric Vehicle

Abstract: Lithium-ion batteries (LIB) are being widely used as energy storage systems for Electric and Hybrid Electric Vehicles. The LIBs are particularly sensitive to temperatures and uncontrolled heating may lead to thermal runaway hence, a battery thermal management system is required to prevent the thermal abuse of the batteries. An efficient battery thermal management system ensures that the battery is working in its optimal temperature range thus, increasing its cycle life and performance. In this study, the heat generation profiles have been calculated for various drive cycles namely, US06, FTP-75, and UDDS, which were validated by a thermo-electric mathematical model in MATLAB Simscape. It was found that a cooling plate with an S-channel design is the most suitable for heat exchange applications and a mass flow rate value of 0.4 kg/s gives an optimum compromise between the heat transfer and the back pressure developed. The control strategy proposed in this research work regulates the battery temperature within the specified limit keeping the parasitic power at a minimum.

Water Absorption and Thickness Swelling Behaviour of Woven Roselle Fibre Epoxy Composites

Abstract: The effect of roselle fabric weave pattern on water absorption and thickness swelling behaviour of woven roselle fibre composites has been investigated. Roselle fabrics with various weaving design such as plain, twill, satin and basket are used in this study. All composites are produced using hand layup process. The water absorption and thickness swelling behaviour of all composites are studied as per ASTM standards. The test samples were immersed in distilled water at room temperature and change in weight and thickness of the test samples recorded at every 24 hour time interval. For all composite samples, saturation in water absorption and thickness swelling was observed after 264 hours of water immersion. Result revealed that the plain-woven composite yields higher resistance to water absorption and thickness swelling than other types of composites.

Effect of Extended Inlet and Outlet Lengths on Transmission Loss of Double Expansion Chamber Reactive Muffler

Abstract: Internal combustion engines are one of the major causes of noise emissions. As in different industrial equipment, locomotives, and vehicles, the engines have a wide application base. Exhaust noise and noise that is created due to friction of different parts share the extreme input to noise pollution. A muffler is a means used by the exhaust system to reduce noise. For the reduction of noise, it is placed alongside the exhaust pipe. The decrease in the exhaust noise level is controlled by muffler construction and operating techniques. Therefore, the muffler configuration plays an important role. In this research work, an effort has been made to study the effect of parameters like different lengths of Extended Outlet (EO) for constant lengths of Extended Inlet (EI) elements in both chambers of Double Expansion Chamber (DEC) reactive muffler with an external connecting tube on transmission loss. It is observed that, as the length of EO is increased from L/5 to L/3 keeping EI constant, the average transmission Loss for the models decreases. The acoustic performance of the muffler is assessed by using COMSOL Multi-Physics and experimental validation.

Exhaust Gas Recirculation as a NOx Reduction Technique for Modified POME Fuelled Diesel Engine

Abstract: The exhaust gas recirculation (EGR) consists of reverting a certain portion of the exhaust gases into the engine cylinder. EGR dilutes the air-fuel mixture in the cylinder reducing the combustion chamber temperature and NOx with a penalty in the value of brake thermal efficiency. EGR as a NOx reduction technique for modified POME fuelled diesel engines has been investigated in the present work. The EGR rate is varied from 0% to 20% for the present study. An EGR rate of 10% has been optimized which results in the decrease in brake thermal efficiency by 3.4%, peak pressure (PP) by 5.6%, heat release rate (HRR) by 10.8% and oxides of nitrogen (NOx) by 1.2% as compared to that without EGR. An increase in emissions such as carbon monoxide by 5%, unburnt hydrocarbons by 10.5% and smoke by 12.8% are observed.

Microstructure and Structural Comparison between Additively Manufactured Metal and Ceramics

Abstract: As we know additive manufacturing helps in reducing the manufacturing time as well as helps in advancing the complexity of the structure. Along with several benefits the method proposes it is very important to keep a track on what how many properties are adversely affected or benefited which helps in optimized planning and projects a significant improvement when kept parallel to the cost efficiency of the product. In order to have such kind of observation it is necessary to map the granular trajectory of the material while going through the process. While additive manufacturing is largely implied upon polymers and metals to a certain extent, ceramics have also seen their part of technological advancement. Both metal and ceramics are equally important and opposite to one another. If somehow, we are able to exploit the benefits of both the materials while on additive manufacturing arena the compound would be highly cost efficient and customization friendly. This paper discusses the micro structural properties and evolution of both metals and ceramics and also on metal matrix composites which are highly in demand in recent times.

Evaluation and Optimization of Plastic Pyrolysis Blends Performance on Diesel Engine with Ethanol Additive using Full Factorial Design

Abstract: Hydrocarbons, present in plastic, are a great fuel source because of their high energy density. The disposal of waste plastic offers major potential for energy conservation and recovery. This research focuses on recovering energy from waste plastics as a potential alternative fuel source for automobiles. This study aims to evaluate the performance of Plastic Pyrolysis Fuel (PPF) produced by the pyrolysis of low-density polyethylene. Ethanol is an attractive alternative fuel since it is produced from renewable bio-resources and acts as an oxygenated to allow for emission reductions in diesel engines. Three distinct ratios of PPF were mixed with 15% ethanol as an oxygenated addition to producing tertiary fuel blends. The performance and emission requirements of a single-cylinder direct injection diesel engine are examined in this study. Specific fuel consumption decreases for P20E15 about 3.5% to 7.8% with diesel. The carbon monoxide emissions from P20E15 were about 4.2% to 6.8% lesser than diesel and hydrocarbon reported with a decrease of 6% to 13.43%, at the different loading. The smoke produced by the P20E15 blend is decreased by around 24% when compared to diesel. The results were analysed further using the full factorial design technique to determine the most optimal running condition.

Customized Design of Inductive Sensor for an Early Detection of Cracks in Indian Rail Transport

Abstract: The objective of this paper is to provide a solution to a serious issue in today’s world of transportation through railways. The practice to examine the flaws which leads to serious effects in rail track is rail inspection. Among the world countries, Indian railways are the fourth-longest, but when it comes to reliability and safety it lags to provide world standard. As a result, if the track is damaged, it leads to severe loss of valuable human lives and property. This derailment in tracks is caused due to cracks in the rails. Therefore, an early crack detection and protection system is required to save the lives. This paper proposes a customized design of an inductive transducer and crack detection system on railroad tracks to avoid the train accidents. Existing method uses the manpower to identify the cracks and this involves human errors. So, the drawbacks in the existing method can be reduced by the automatic system. Customized inductive sensor is designed and developed using ANSYS. A scaled down model of a cart is fabricated and the inductive sensor is assembled at beneath surface of the cart. The track is acting as a part of the magnetic core for the inductive sensor and voltage is induced in the sensor. The sensor voltage is calibrated to distinguish the magnitude of voltage from the normal to crack.

Emission Trends on an Un-modified Research Engine Run with Alcohol and Cashew-Nut Blends

Abstract: The effects of mixing pentanol, a future generation biofuel, with cashew biodiesel on engine emissions in a constant compression ignition engine were studied. Traditionally, cashew nut oil is converted into biodiesel using the transesterification process. Pentanol, an oxygenating component, is used. Three test fuels namely, CB100 (cashew nut biodiesel), CB90P10 (pentanol mixed with cashew nut biodiesel by 10% volume) and C80P20 (pentanol blended with cashew nut biodiesel by 20% volume) were used in the experiment. It was also examined whether it was feasible to use neat biofuel. Experimental tests concluded that those test fuels would not require any modification to engines. Significant reduction in carbon monoxide emissions is seen when 10% and 20% pentanol were added to the biodiesel.

Application of Oxygenated DEE and Ethanol on the Performance and Emission Characteristics of Diesel-Fuelled CI Engine in the Context of Variable Injection Timing

Abstract: In a direct injection CI engine, the ignition delay and combustion characteristics are very sensitive to changes in fuel injection timing as the peak pressure and temperatures change significantly close to TDC. The addition of DEE and ethanol to diesel fuel causes retarding of the dynamic injection timing. Hence, it desires to study the effect of variable injection timing on emission and performance of DEE-ethanol-diesel blended CI engine and find out the optimum injection timing. In this experimental study, the optimum performance DE8E10D (8% DEE, 10% ethanol and 82% diesel by volume) blended fuel is selected for investigation. The engine tests are carried out at no load, 25%, 50%, 75% and 100% of full load with 3° and 6° advancement, base injection timing and 5° retarded injection timings. The test results reveal that BTE has improved and the smoke, CO and HC emissions have reduced with advanced injection timing. At full load condition, the 6° advancement in injection timing has reduced the smoke by 10.66% than the base injection timing. A sharp decrease in NOx emissions has been observed in 5° retard in injection timing. Overall, the results validate that 6° advancement is the optimum injection timing which has improved the overall performance and emissions of DEE-ethanol-diesel blend fuel in the CI engine.

Experimental Investigation on Low-Velocity Impact Strength of E-Glass/Carbon Fiber Reinforced Hybrid Polymer Composite

Abstract: Plenty of research works has happened on the polymer matrix composite with different fiber as reinforcements from last 3 decades to satisfy aerospace, automotive, marine and military and defence industries requirements. Although, several reinforcements materials like glass fiber, carbon fiber, Kevlar fiber, etc. are used in the development of advanced materials, producing efficient and high-performance material has become a primary requirement of the industries and this had led to research and designing of hybrid composites. In this work, E glass/carbon fiber reinforced epoxy 5052 polymer matrix composite is prepared by vacuum bag moulding technique with varying the thicknesses from 2mm, 3mm to 4mm. A low-velocity impact test is conducted for the composite laminates for different impact energies. The force-time relationship is studied. The decrement in contact time and increment in peak force is noticed with an increase in the thickness of the composite laminates. Ultra-sonic scanning is also performed to understand the delamination at the damaged area.

Fatigue Analysis of a Forged Medium Carbon Low Alloy Steel Quenched in a Polymer for Vehicle Structures Applications

Abstract: The fatigue properties of medium carbon low alloy forged Steels (EN 18, EN19, EN 24 and EN25) for untreated (forged) and polymer quenched samples are investigated. A dissolving temperature of 855ºC with a soaking period of 60 minutes followed by step tempering of 575ºC and 220ºC was used for the heat treatment. Thereafter quenching was performed in a polymer (polyethylene glycol 10% and 30%) separately. Fatigue tests were performed on both untreated and polymer quenched samples. The polymer quenched samples outperform the untreated samples. The fatigue analysis has been carried out using ANSYS and substantiated by the experimental results for the polymer quenched samples loaded to 30% of UTS. The heat-treated specimens had a fine-tempered martensite structure with a trace of ferrite, which enhances the toughness characteristics required for vehicles structures applications.

CFD Simulation of Showerhead Jet Impingement at Leading Edge of a Gas Turbine Blade

Abstract: The performance of gas turbine improves with increase of turbine inlet temperature and leading edge of the turbine blades are subjected to the highest temperatures. To decrease the temperature, jet impingement technique is used for the leading-edge blade cooling. In this present study, showerhead arrangement is used for the jet impingement cooling. This showerhead arrangement consists of a central jet and it is surrounded by four jets resembling a shower. As the area/region of influence in the showerhead arrangement is hemi-spherical, an improved heat transfer is expected. The cross-section of the jet impinging holes is circular. The study is carried out by varying the Reynolds number from 11000 to 50000 for a jet impinging length of R/2. Steady-state simulations are carried out using commercial CFD code, ANSYS Fluent and turbulence model used is kω-SST. Wall temperature distribution decreases with increase in Reynolds numbers and it is observed to be minimal at the jet impingement point (i.e., stagnation point). Wall temperature distribution of the showerhead arrangement with straight impingement tubes is lesser compared to showerhead arrangement with bended impingement tubes. Mixing of jets prior to impingement on the wall is visualized for showerhead arrangement with bended impingement tubes leading to ineffective cooling for this arrangement. Nusselt number of the showerhead arrangement with straight impingement tubes are higher compared to showerhead arrangement with bended impingement tubes indicating better convective heat transfer.

Review on Hybrid Rocket Engine: Past, Present and Future Scenario

Abstract: A Hybrid Rocket Engine (HRE) in a conventional way refers to a combination of fuel as solid and oxidizer in the liquid or gaseous phase. This combination has received significant attention in the scientific community due to its intriguing characteristic of reducing chemical explosions and enhancing operational safety. Alongside, the impact on environmental sustainability can be escalated to a reasonable scale. In this context, the current paper emphasizes the major challenges involved with combustion, design of reaction mechanism, low regression rate, choosing the right fuel and poor mechanical properties. This review will help the scientific community to establish a state-of-art technology that would resolve the current challenges to provide a sustainable result. At the same stretch, most of the works haven’t realized this technology to a commercial value. Hence the current review shall focus on the works cited in the global community and lacunae for the transfer of technology-to-technology readiness level.

Turbulent Flow in Forced Convection Heat Transfer - Numerical Validation

Abstract: Forced convective heat transfer of airflow through circular pipe with constant heat input and different free stream velocities is numerically validated. The significance of the present work is that the suction flow has been employed in the forced convection set up domain kept in the wind tunnel. From first law of thermodynamics and applying the energy balance equation, experimental heat transfer coefficient is determined. Further correlations are used to validate the experimental results. Although correlations provide reasonable estimates from the point of feasibility and accuracy, computational methods are used to estimate the convective heat transfer coefficient. Hence in this paper experimental, theoretical and computational analysis is carried out. The results reveal that the numerical validation is an effective tool from the point of feasibility and accuracy to determine the convective heat transfer coefficient.

Experimental Analysis of Double Pipe Heat Exchanger with V-cut Twisted Tape Inserts using PCM Dispersed Nanofluids

Abstract: The performance of a double tube heat exchanger with V-cut twisted tape inserts (VCTT) and phase change material (PCM) dispersed nanofluid is investigated experimentally. The three water-based Al2O3, PCM, and Al2O3+PCM nanofluid with different concentrations (0.01-0.1% vol.) are used. The impacts of different geometric parameters, i.e., twist ratio (TR), depth ratio (DR) and width ratio (WR) of VCTT inserts on Nusselt number (Nu), friction factor (f) and entropy generation are examined. The outcomes expose that Nu and f increase as particle concentration increases and twisting ratio decreases. A higher Nu and f are generated by a higher DR or a lower WR. In all cases, the entropy generation of nanofluid is found to be lower than that of water. For all working fluids, a rise in TR, a fall in DR, and a rise in WR increases overall entropy generation.

Computational Investigation on Phase Change Material based Hybrid Battery Thermal Management System for Electric Vehicle

Abstract: The future of the automobile industry is moving towards the electrification of vehicles due to the increase in pollution and global warming. The thermal management of the battery is necessary to enhance the performance of the battery module at extreme operating conditions. Battery thermal management systems using phase change material can be used to control the temperature extremity and to achieve uniformity in temperature inside battery module. In this work, the conventional battery layout system is modified to induce the passive cooling with the use of PCM (paraffin wax) which has been placed around the periphery of each cell in the battery pack. Different thickness of PCM layer 2mm, 3mm and 4mm have been taken. This reduces the weight and cost compared to the existing PCM based BTMS. This also ensures improvise in the efficiency of the battery. The battery thermal behaviour is studied using ANSYS for various discharge rate condition (4C, 3C, 2C and 1C) with air assisted cooling system having an air flow rate of 4m/s. From the analysis, it is found that maximum temperature of a battery pack at 4C discharge rate without any BTMS is, about 60C. Elevated temperature of the battery pack covered with a PCM, for same discharge rate with same air flow rate for 2mm is 33.5C and for 3mm it is 34.4C and for 4mm it is 34.07C which falls under the optimal temperature. While adding expanded graphite to the PCM it is found that the temperature reduces to 30C for 2mm thickness PCM.

Investigation of Flow Separation Over NACA 24015 and 24021 Airfoils using Flow Injection Method

Abstract: Few explorations used different stream control techniques to work on the streamlined presentation of different airfoils by postponing the stream partition. In this paper, a complete investigation of NACA 24015 and NACA 24021 airfoils was done in CFD at different approaches for various free stream speeds. CATIA V5 R20 was utilized to make the 2D model of the airfoils and the SST K-e disturbance model was used for CFD investigation. Full investigation is performed on a typical airfoil to comprehend the stream conduct at different point of assaults and admission speeds and the equivalent is accomplished for vented airfoils also by concentrating on the suitability of the log jam surrendering approach.

Combustion Characteristics of Multicomponent Fuel Droplets

Abstract: The present study investigates the combustion characteristics of the multicomponent diesel-water (D-W) emulsion fuel droplets. The stable blends obtained by using Surfactant, Span-80 (s) and three different fuels viz., WD1 (D-95%, W-3%, S-2%), WD2 (D-94%, W-4%, S-2%) and WD3 (D-96%, W-3%, S-1%) are subjected to the pendant mode of droplet combustion in the ambient conditions. The blend's stability depends on surfactant and water compositions. WD1 exhibited a higher viscosity W/s ≥ 1 at near-boiling point of the dispersed fluid. The higher viscosity droplets resulted in fewer secondary atomization. WD3 with lower viscosity (W/s >1.5) exhibited multiple cycles of the micro-explosion events. The cycles of micro-explosion depend on water to surfactant concentration. The blend with lesser surfactant exhibited the lesser cycles of explosion events. The regression rate of the droplets was fitted using d2-law. WD1 possesses the least burn time. The vapors of low volatile fluid, i.e., water vapor were trapped inside emulsion the droplets. Upon receiving the constant heat from flame surface, the surface of the droplets gets highly corrugated due to the capillary oscillations. Subsequently, the trapped bubbles of the less volatile fluid are ejected out as the daughter droplets. These ejections are more predominant in higher surfactant concentrations. The ejections frequency reduces with an increase in water %. This enabled the rapid burning of the droplet when compared to base fuel combustion.

Design and CFD Analysis of a Rear Wing of a Motorsport Car

Abstract: The rear wing of a motorsport car is one of the 3 main components to produce the downforce required by the car to take a corner with the maximum speed possible. This paper aims to design and analyse the rear wing of a motorsport car. The design consists of a lower wing element (main plane), an upper wing element (flap) and the endplates. In this study, the rear wing is designed as per the FIA 2020 F1 technical regulations and is analyzed using Computational Fluid Dynamics (CFD). The rear wing model is designed using Autodesk Fusion 360 and the analysis is made using Autodesk CFD. Benzing airfoils were used in this project as the wing elements. The results of the stock and modified model are compared and discussed. The results show how the modified version of the endplate has better aerodynamic properties than the stock model. The whole rear wing assembly has also been analysed and the results were discussed.

Failure Characterization of Flax/Epoxy Composite Materials with Filler Under Acoustic Wave

Abstract: Researches on bio-composites are increased due to their environment friendly. Some research shows a good improvement in their mechanical property with the polymer/synthetic composites. In this paper, the damage characterization of flax epoxy composite with alumina powder as filler under acoustic emission at various stages are studied. For this work, the alumina powder with various percentages such as 3% and 5% are chosen. In this project, tensile and flexural tests are performed. From the tensile test peak load and strain functions are calculated. Acoustic emission is non-destructive technique used to find the damage mode. AE has the advantage over other method due to its high sensitivity. The three-point bending is performed on the filler infused flax/epoxy composite to evaluate the flexural damage at various percentage of filler composition. The damage characterization is studied based on the frequency obtained over the time. These failure modes such as delamination, matrix cracking fibre damage are associated with frequencies are evaluated using standard mode of damage. Duration (μs) vs. amplitude (dB) and force (N) vs. position (mm) curves are plotted to evaluate the damage. The real time various damage levels occurs during flexural loading and it was evaluated using AE techniques.

Impact Load Testing of Friction Stir Welding of Aluminium 6082-T6 Alloy

Abstract: Solid-state friction stir welding is a joining technology that allows alloys that are difficult to fuse using traditional fusion methods to be joined. Structures that are not welded are more expensive and heavier, whereas those that are welded are less expensive and lighter. They have benefited from their application due to the difficulty of joining high-strength aerospace aluminium alloys and other metallic alloys using traditional fusion welding. Friction Stir Welding (FSW) produces precipitation-strengthened aluminium alloys with a variety of microstructures and mechanical properties. The chemical composition of an alloy has an impact on its final and initial microstructure. These variables have a significant impact on the weld microstructure and strength, in addition to welding parameters, thermal cycle and the use of auxiliary cooling systems, tool geometry and thickness. FSW, a new green solid state joining method, was used to join high-strength aerospace aluminium alloys.