Vellore Institute of Technology (VIT) is a private university located in&nbsp;Tamil Nadu, India. Founded in 1984, as Vellore Engineering College, the institution offers 20 undergraduate, 34 postgraduate, four integrated and four research programs. It has campuses in Vellore, Amravati, Bhopal and Chennai.

VIT is one of the top ranked private universities in India according to NIRF, THE and QS Rankings.&nbsp;Govt. of India has recognized&nbsp;VIT, Vellore as an&nbsp;Institution of Eminence. This has allowed VIT to take independent quality initiatives and move up in world ranking.

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VIT University

Department of Automotive Engineering

Fuel sloshing occurs in vehicle when it accelerates or decelerates. It generates high kinetic energy with unpleasant noise. This fuel sloshing leads to vehicle imbalance. This vehicle instability may occur when the fuel to weight ratio is high. In automobiles, the fuel sloshing generates unpleasant noise which is not expected from the present ones. So, this work presents the use of baffles at different positions in the fuel tank to suppress the fuel sloshing. Generally this phenomenon is seen in High Density Polyethylene (HDPE) tanks which are strong and light in weight. Introduction of baffles in the HDPE tanks is an onerous process through blow moulding. So the present work mainly focuses on the simulation of the slosh experiments to analyse the baffle design. The result depends upon the number of baffles, location of the baffle and its shape. The highest noise is generated only when the fuel hits the top of the tank. The baffle is designed in such a way that these noises are reduced. The height of the baffle should be sufficient enough to reduce the flow of fuel. The work mainly focuses over the selection of appropriate height of the baffle which gives optimum result with less effect on the fuel capacity of the tank. For this work, the fuel tank is modelled with Solidworks 2011. The fuel tank is meshed in ICEM CFD. It is solved in Ansys CFX 12.0. The Turbulent kinetic energy, force and velocity produced by the fuel during sloshing are calculated. The kinetic energy produced by the fuel produces the stress at the ends when reaching the ends of the tank. So the use of baffle reduced the noise and as well as the stress created at the ends. The product life cycle of the tank is also improved. © 2006-2014 Asian Research Publishing Network (ARPN).

School of Mechanical Engineering

Vellore Campus

World University root node

Department of Thermal and Energy Engineering

ARPN Journal of Engineering and Applied Sciences

Design of fuel tank baffles to reduce kinetic energy produced by fuel sloshing and to enhance the product life cycle

This work is concerned with the characteristics of incompressible viscous flow inside a two-sided lid-driven cavity with its two opposite walls moving with a constant velocity in parallel direction and in antiparallel direction by Lattice Boltzmann method (LBM). The model used in the present work is two-dimensional nine-velocity (D2Q9) square lattice as it gives more stable and accurate result when compared to two-dimensional seven-velocity (D2Q7) hexagonal lattice. The characteristics of flow problem are investigated for different Reynolds number and also for aspect ratio, K = 2.0 and 5.0. The formation of different vortices with the variation of Reynolds number for parallel and antiparallel motion is studied in detail. To sum up, the present study reveals many interesting features of two-sided lid-driven deep cavity flows and demonstrates the capability of the Lattice Boltzmann method to capture these features. © 2006-2014 Asian Research Publishing Network (ARPN).

Examination of the lattice boltzmann method in simulation of manufacturing

Numerical simulation is currently applied in all engineering applications. The application considered in the present work is the simulation of the flow field and combustion phenomena in a diesel engine. The physics underlying the combustion and pollutant formation phenomena in a direct-injection diesel engine is quite complex due to the various processes such as the mixing of fuel with air, turbulence of the flow field, and combustion phenomena followed by the formation of new chemical species. All these processes are modeled using conservation principles and stochastic processes. They are finally expressed in the form of partial differential equations. These are then converted into algebraic equations after discretization by the finite-volume method. The final sets of equations are solved by a pressure implicit splitting of operators algorithm and the state-of-the-art solver is accelerated using the multi-grid technique.With regard to the physical aspects of the present work, two different combustion chambers are compared in this three-dimensional computational fluid dynamics (CFD) simulation for the whole cycle of a four-stroke direct-injection diesel engine. From the experimental engine setup, the crank angle and in-cylinder pressure data are observed using sensors and a data acquisition system. The results between the measurements and calculations are in close agreement for the whole cycle considered for one of the combustion chambers, which is the hump (re-entrant type). The hump in the toroidal combustion chamber is removed (flat type) to study its effect on the flow field and combustion using CFD while maintaining exactly the same compression ratio. The results also confirm that the turbulence in the flow field is enhanced in the case with hump (re-entrant type) compared with the flat type. With the flat type, the squish flow and combustion during the compression and expansion strokes is affected significantly. This results in a loss of 11% peak pressure when compared with the re-entrant type. The results also confirmed that the piston geometry significantly influences the in-cylinder flow during the intake stroke. The bowl shape plays a significant role at the end of compression and in the early stage of the expansion stroke. The NOx emissions are slightly higher while the CO and CO2 emissions are relatively less in the re-entrant type. © 2014 by Begell House, Inc.

Mechanical

Chennai Campus

Computational Thermal Sciences: An International Journal

COMPARATIVE EVALUATION OF THE RE-ENTRANT AND FLAT TOROIDAL COMBUSTION CHAMBERS IN A DIRECT-INJECTION DIESEL ENGINE USING COMPUTATIONAL FLUID DYNAMICS

Biodiesel is an emerging alternative to fossil diesel for use in compression ignition engines. From environmental standpoint, an increase in nitric oxide (NO) emission from biodiesel fueled engine has been a major concern. Several investigations suggest the role of unsaturated methyl ester as a contributor to biodiesel-NO penalty. The chemical simplicity of biodiesel compared to fossil diesel makes their composition effects amenable to a systematic analysis. In this study, the effects of saturated palm and unsaturated karanja (Pongamia pinnata) biodiesels and their blends (Bio-mix) on compression ignition engine performance, combustion and NO emission are investigated. The combustion and emission characteristics of these fuels are compared with fossil diesel that the neat biodiesel fuels result in improved exhaust emissions except NO with a penalty in fuel economy. However, the use of biodiesel blends of palm and karanja resulted in reduction of the total unsaturated content to an extent of 40% relative to neat karanja. At this condition, a maximum decrease of 14% is observed in the exhaust NO concentration. This also corroborated with a reduction in measured iodine value of biodiesel samples. Copyright © 2014 SAE International.

SAE Technical Papers

Controlling Nitric Oxide in C i Engine - Bio-Mix Approach

VIT Unitversity

IOSR Journal of Mechanical and Civil Engineering

Finite Element Analysis of Universal Joint

Different medium access control (MAC) layer protocols, for example, IEEE 802.11 series and others are used in wireless local area networks. They have limitation in handling bulk data transfer applications, like video-on-demand, videoconference, etc. To avoid this problem a cooperative MAC protocol environment has been introduced, which enables the MAC protocol of a node to use its nearby nodes MAC protocol as and when required. We have found on various occasions that specified cooperative MAC establishes cooperative transmissions to send the specified data to the destination. In this paper we propose cooperative MAC priority (CoopMACPri) protocol which exploits the advantages of priority value given by the upper layers for selection of different paths to nodes running heterogeneous applications in a wireless ad hoc network environment. The CoopMACPri protocol improves the system throughput and minimizes energy consumption. Using a Markov chain model, we developed a model to analyse the performance of CoopMACPri protocol; and also derived closed-form expression of saturated system throughput and energy consumption. Performance evaluations validate the accuracy of the theoretical analysis, and also show that the performance of CoopMACPri protocol varies with the number of nodes. We observed that the simulation results and analysis reflects the effectiveness of the proposed protocol as per the specifications. Copyright © 2014 by the IETE.

IETE Journal of Research

Performance analysis of a cooperative MAC protocol of wireless ad hoc networks

Three-dimensional flow and temperature fields within a 19-pin wire-wrapped fuel bundle of fast reactor with internal blockage have been predicted by Computational fluid dynamic (CFD) studies. Simulations are carried out for a stream-wise length of seven helical pitches. Blockage geometry (shape and size), its radial position and blockage porosity which influence the clad temperature and hence increase the risk of sodium boiling, are systematically varied in a parametric study. Clad temperature, cross-stream sodium velocity and cross-stream temperature distributions are investigated in detail. Axial variation of clad temperature is seen to exhibit strong fluctuations due to the interaction of helical spacer wire and coolant flow through a subassembly with porous blockage. The maximum difference in the circumferential temperature of clad, which is a critical parameter for fuel pin mechanical design, is large in pins that are partially exposed to blockage. Effect of porous blockage is found to be limited to the porous zone and the peak clad temperature is proportional to the volume of the porous zone. Peak temperature in the blockage is strongly influenced by the radial extent of blockage and it is higher if the radial extent is larger. Maximum difference in the circumferential clad temperature is relatively low for a corner blockage compared to that of a central blockage. Sodium boiling is imminent in fuel pin bundle with six blocked sub-channels located at the centre when porosity value reduces below 45%. © 2014 Elsevier Ltd. All rights reserved.

Annals of Nuclear Energy

Thermal hydraulic effect of porous blockage in fuel subassembly of sodium cooled fast reactor

Direct Metal Laser Sintering(DMLS) is a sequential layered manufacturing method to produce any desired three dimensional parts with simple or complex shapes with no or minimum post-processing. In this study Bronze-Nickel powder was used to make the samples. The samples were produced with the optimized set of parameters such as sintering speed, scan spacing, hatch type, hatch distance and infiltration based on previous studies. To investigate the tribological behavior of the sintered components for functional applications, reciprocating wear tests under lubricated condition were carried out. A ball-on-flat configuration was chosen for the tests. Using Design of Experiments, Taguchi's modified L9 orthogonal Table has been implemented to carry out the experiments. Hardness, load and temperature were the three parameters considered and three levels were chosen for each to create the orthogonal array. Wear tests were carried out with the set parameters and wear rates of the DMLS samples were found out. ANOVA statistical method was used to find the influence of major parameter and the contribution of each parameter on the wear rate of the samples. It has been found that the applied load, one of the selected test parameters had more influence on lubricated wear as compared to other parameters. © 2006-2014 Asian Research Publishing Network (ARPN).

Department of Design and Automation

Investigations on the lubricated wear of direct metal laser sintered components for functional applications

Biodiesel fuel is found to be a promising alternative for the petroleum diesel based on the results published by the researchers for a decade. Biodiesel fuel is renewable and non degradable fuel. Many countries use biodiesel fuel for automotives to meet the crisis due to the depletion of the petroleum fuel and to meet the stringent emission norms. Various researches have been carried out with different biodiesel fuels with vegetable oil as the source and appreciable results were reported. Few biodiesel fuels which have been already tested are Jatropha, Pongamia, Mahua, neem, cotton seed, etc. In this experimental work, Adelfa biodiesel blend is used as the test fuel. The emission and performance characteristics were compared with three other different biodiesel fuel blends. Appreciable results imply that Adelfa biodiesel (Nerium oil methyl ester) can be a futuristic biodiesel fuel, which has a good compatibility with the direct injection (DI) diesel engine without any major modification. Moreover, Adelfa can be cultivated in a non agricultural land with fewer sources of water. It is widely spread over all major countries of Asia. Experimental investigations have been carried out on a single cylinder DI diesel engine with standard engine specifications. In this experimental work, various Adelfa biodiesel blends is compared with reference fuel (diesel) to choose the best blend which gives a closer performance to diesel. The comparative analysis with other biodiesel fuels has also been done and results have been discussed. © 2014 Science China Press and Springer-Verlag Berlin Heidelberg.

Chinese Science Bulletin

Adelfa: A futuristic biodiesel fuel for DI diesel engines: A comparative experimental investigation

Metal duct or channels of rectangular cross section with black selective coating has an application in solar air heaters. Increase in heat transfer rate is achieved by suitably modifying the absorber surface with fins, corrugations, honey comb structure etc. In the present article numerical study is performed using computational fluid dynamics (CFD) on a rectangular metal duct having transverse square wire rib roughness of small diameter created artificially on the absorber surface. The design parameters of the analysis are the flow Reynolds number, hydraulic diameter roughness pitch and height. The 3D analysis is performed using ANSYS FLUENT 12.1 code with Renormalization-group (RNG) k-e model having the mesh model under five lakh nodes to investigate the heat transfer and fluid flow characteristics. The results of smooth duct are compared with results from literature and found to be in good agreement. The ratio of increase in heat transfer to friction factor referred as energy gain ratio with the use of artificial roughness is estimated for range of parameters and optimum performance condition is arrived. The maximum value of energy gain ratio is about 1.31 times more compared to the plain duct for the range of operating parameters investigated. © 2006-2014 Asian Research Publishing Network (ARPN).