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In conventional turbojet engine the turbine power is being utilized to rotate the compressors whereas in the Hybrid air breathing propulsion system, an electric motor will be used to give power input to rotate the compressor. So, the space available without a turbine could be used to accommodate a contra-rotating compressor where alternative blade rows rotate in a counter direction. Previous studies show the contra-rotating compressors are superior to conventional ones. The objective of the present work is to design a contra-rotating compressor and to numerically analyse the effects of rotational speed of rotors and inlet Mach number on the performance of the same. Numerical simulations are performed for different rotational speed values of rotors ranging from 5000 RPM to 15000 RPM and with four inlet Mach numbers starting from 0.5 to 0.8.

This paper aims to design a system to generate energy from flowing wind due to the motion of a vehicle on the road or from the flow of wind in compact areas to utilize the wasteful energy into a useful one. It is envisaged via a design and the improvement in efficiency of a Savonius Vertical Axis Wind Turbine and coupled in an integrated system with a Triboelectric Nanogenerator (TENG) that can generate a good amount of electrical energy. Aerodynamic calculations are performed numerically using a CFD Software, and the efficiency of the TENG is evaluated analytically. The Turbine's coefficient of power is validated with the literature for an inlet velocity of 7 m/s with a Tip Speed Ratio (TSR) of 0.75 and found to reasonably agree with that of experimental results. The baseline design is modified with a new blade arc angle and rotor position angle based on the recommended parameter ranges suggested by previous researchers.

Automotives play a very important role in day-to-day human lives. The exhaust gas emitted from automotive vehicles of current technologies is one of the major contributions to global temperature increment. It is important to develop a system that can conserve energy and incorporate it into current vehicles which are in use. Phase change materials (PCM) are well known for energy storage applications because of their crucial thermophysical property known as latent heat of fusion. The gas from the exhaust pipe of automobiles can be considered a turbulent jet. With this assumption in this study, a system is proposed by combining jet impingement and phase change material at the exhaust pipe of automobiles to recover the thermal energy which is being let out into the atmosphere as waste. Liquid Gallium is chosen as a phase change material for this study because of its high thermal conductivity nature compared to other hydrocarbon-based phase change materials.

Numerical simulation has been performed to study the heat transfer enhancement from the vertical heated wall surfaces with the help of rising bubbles due to the buoyancy force. The effect of wall proximity and bubble shapes are investigated for three wall shapes such as plane wall, wavy wall and triangular wall. Numerical solution is obtained by solving both the thermos-fluid governing equations and the Volume of Fluid (VOF) advection equation along with the Piecewise-Linear Interface Construction (PLIC) algorithm available in ANSYS-Fluent, an FVM based commercial CFD code. The results observed in the three types of wall geometries were showing the heat transfer differently for the 3 mm bubble. For the plane wall from the rise of the bubble to 0.3 seconds the temperature gradient is 10 K whereas for the curved and triangular wavy walls these gradients are 9.6 K and 17.23 K respectively. and after 0.6 seconds, this gradient is almost the same for all the wall shapes.

The present numerical analysis aims at studying the effect of changes in profile of truck-trailer on aerodynamic drag and its adverse effect on fuel consumption. The numerical analysis is carried out using commercial CFD software, ANSYS Fluent, with k-ω Shear tress transportation (SST) turbulence model. In present study four models of truck were analysed, including baseline model at different Reynolds numbers, namely 0.5, 1, 1.5 and 2 million. In order to enhance fuel consumption, various profile modifications have been adapted on baseline truck-trailer model by adding a spoiler and bottom diffuser at the rear of the truck, by providing vortex generator at the rear top of the truck and by adding boat tail at the end of trailer. The comparison has been done with respect to coefficient of drag, coefficient of pressure, pressure contours, and velocity vectors between all four cases.

Recent years, researches are more focused on various enhancement methods for compact heat exchangers without altering the surface area of the heat exchangers. The advancements in the area of Nano fluids with better thermal properties have helped in development of light-weight, highly efficient automobile radiators. The main objective of this project is to increase the thermal performance of the radiator and thereby reducing the size of the radiator. In this project a numerical model with porous medium approach was developed and validated. Nano fluids (Aluminium oxide, Copper oxide, Graphite) of different volumes (ranging from 1%-13% in an interval of 2) are used along with water and it was observed that the heat transfer rate of the radiator is increased by 4.49% and the volume of the radiator is reduced by 5.4% for the addition of 5% of Aluminium oxide in water.

Heat transfer analysis in the combustion chamber of internal combustion engine is crucial to design the combustion chamber. Manufactures will always look for the durability, better engine performance and also on the material cost for designing the combustion chamber. This will be achieved by designing the efficient combustion chamber effectively. The purpose of this paper is to determine the Adiabatic Flame Temperature using stoichiometric equations and find the gas temperatures at different points in the ideal diesel cycle. These values are used in the existed heat transfer coefficient equations and estimate the heat transfer to the coolant through the cylinder wall using one dimensional heat equation. This theoretical value of heat transfer rate is compared with the experimental heat transfer rate of the three cylinder engine. The average error percentage of the theoretical and experimental values is less than the 15 %.

The maximum power produced by the Engine is utilized in overcoming the Aerodynamic resistance while the remaining has been used to overcome rolling and climbing resistance. Increasing emission and performance demands paves way for advanced technologies to improve fuel efficiency. One such way of increasing the fuel efficiency is to reduce the aerodynamic drag of the vehicle. Buses emerged as the common choice of transport for people in India. By improving the aerodynamic drag of the Buses, the diesel consumption of a vehicle can be reduced by nearly about 10% without any upgradation of the existing engine. Though 60 to 70 % of pressure loads act on the frontal surface area of the buses, the most common techniques of reducing the drag in buses includes streamlining of the surfaces, minimizing underbody losses, reduced frontal area, pressure difference between the front & rear area and minimizing of flow separation & wake regions.

Nowadays, Diesel emission control strategies are stringent across the globe which caused the rise in need of diesel after treat treatment devices that are more reliable and efficient. The optimized design of the catalytic converter aids in the durability of the product as well as the improvement in efficient operation of the Indian driving cycle. By changing the convergent and divergent cone angles of the catalytic converter, the consequential decrease in pressure drop leads to efficient flow of exhaust gases. The purpose of this study is to design, test, and analyse the catalytic converter in order to reduce the pressure drop in the exhaust system of a naturally aspirated diesel engine using both experimental and CFD techniques. In this study, a Diesel Oxidation Catalyst Catalytic Converter is investigated. For numerical analysis, ANSYS Fluent is used.

During flight an emergent circulatory flow pattern named vortex is observed at wing tips producing induced drag. An approach to reduce this effect is by implementing winglets. Winglets are small wing-like lifting surfaces, fitted at the tip of some wings, usually with the objective of decreasing trailing vortex drag and thereby increasing the aerodynamic efficiency of the wing. The aim of the project is to design and analyze the effect of winglets for Cessna 152 by varying the cant angle and sweep angle. This model has been selected since it provides a good choice for Pilots first airplane. A baseline wing model was designed in CATIA V5, correspondingly wings with winglet models were designed with a fixed taper ratio of 0.2 and different cant and sweep angles. The lift to drag ratio is evaluated at different angles of attack by varying winglet design parameters.

The present numerical analysis aims at studying the effect of changes in profile of van on aero-acoustic noise and aerodynamic drag. The numerical analysis is carried out using commercial CFD software, ANSYS Fluent, with k-epsilon & Large Eddy Simulation turbulence models. In present study five models of truck are analysed, including baseline model at different Reynolds numbers, namely 0.391, 0.415 and 0.457 million. In order to reduce the aero-acoustic noise, various profile modifications have been adapted on existing van model by adding a top and bottom diffuser at the rear of the truck. The comparison has been done with respect to coefficient of drag, coefficient of pressure, pressure contours for all four cases.

In the present work, it is aimed at developing an integrated approach for combustor modeling involving rapid prototyping and water tunnel testing to assess the cold flow numerical simulations; the physical model will be subjected to cold flow visualization and parametric studies and CFD analysis to demonstrate its capability for undergoing rigorous cold flow testing. A straight through annular combustors is chosen for the present study because of it has low pressure drop, less weight and used widely in modern day aviation engines. Numerical Analysis has been performed using ANSYS-FLUENT. Three dimensional RANS equations are solved using k-ɛ model for the Reynolds numbers ranging from 0.64 x 105-1.5 x 105 based on the annulus diameter. Post processing the results is done in terms of jet penetration, formation of recirculation zone, effective mixing, flow split and pressure drop for different cases.

In the last two decades, most of the advances in exhaust systems such as acoustic filters and mufflers had been developed to attenuate noise levels and emissions as per environment norms. The purpose of this research work is to design, analyze and test an exhaust muffler in order to determine the pressure drop and noise reduction in the exhaust system. Computational Fluid Dynamic simulations were performed using ANSYS Fluent 16.2. The muffler diameter and length were chosen where as perforations and baffles were also considered so as to have the maximum pressure drop and noise reduction. This study is aimed at investigating a reactive perforated muffler. Several designs were considered for maximum pressure drop and the best was finally selected for manufacturing. Experimental testing was carried out with the finalized muffler prototype.

In the present work, bio-diesel produced from Thevatia Peruviana seed oil which is commonly called as Yellow oleander is blended with diesel to investigate the performance and emission characteristics of a naturally aspirated diesel engine. The testing is carried out under 8-mode testing cycle used for off-road vehicles. The extracted bio-oil is subjected to gas chromatography-mass spectrometer to obtain its fatty acid profile. It is then converted into bio-diesel by transesterification process. The properties of bio-diesel produced are conforming to EN14214 standards except for a slightly lower density. Two blends of B10, B15 with diesel are used for experiments. The reduction in power and torque is observed to be proportional to increasing blend ratio. Results show that there is a reduction of 15.71% of CO and 32.30% reduction in HC for B15 blend compared to base line diesel. However, CO2 and NOX emissions are found to be increased for blends as compared to baseline engine.

A numerical study of three-dimensional flow and heat transfer of a rectangular plain with built-in delta winglet type longitudinal vortex generators is carried out in order to enhance the convective heat transfer at the air side of the fin with minimum penalty on pressure drop. Longitudinal vortices develop along the side edge of the delta winglets due to the pressure difference between the front surface (facing the flow) and back surface. These vortices interact with thermal boundary layer and produce a three dimensional swirling flow that mixes near wall fluid with the midstream. Thus the thermal boundary layer is disrupted and heat transfer is enhanced. The efficiency of the delta winglet vortex generators widely varies depending on their size and shape, as well as the locations where they are implemented. In the present study, the longitudinal vortices have been created by the delta-winglet type vortex generators in common-flow-down configuration.

The process of building the engine and its subsequent systems involves usage of metals & its compounds. The current technique is in which the fuel is burned in a combustion chamber wherein the actual combustion progression and its subsequent gases are surrounded by metallic compounds. The part of the heat energy generated in the system is forced to be removed by means of cooling to protect the structural integrity of the engine; nearly 30% of the energy is lost due to cooling. However limitation in structural behavior of metallic materials and limited resource for the production of metals and alloys with superior high temperature structural causes the search for new alternate materials like ceramics, organic synthetic plastic, etc. Thermal Barrier Coating is an attractive and promising method in providing thermal insulation for the engine components due to its good thermo-mechanical properties.