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

This research is aimed to analyse and optimize the inlet manifold of biogas diesel dual fuel engine to improve the mass flow rate of air and gas mixture and hence improving volumetric efficiency of the dual fuel engine. Runner length of the inlet manifold is calculated using Chrysler Ram Theory and Helmholtz Resonator Theory and new runner length is replaced in the existing inlet manifold and it is observed that new runner length gives a considerable increase in mass flow rate of air and hence improving the volumetric efficiency. The biogas was collected from biogas plant of Vellore Institute of Technology and the diesel engine was operated with diesel and bio gas with the help of a T-section joint which allowed the air and bio gas to enter the engine together and then we performed the experiment to calculate the mass flow rate of air and bio gas entering the engine. The experiment was done for the existing runner length of 1 m and the new runner length of 1.58 m, as calculated by Chrysler Ram Theory and improvements were observed in mass flow rates and volumetric efficiency. Emission testing was also done by using the AVL emission system, emission-parameters-like-carbon-monoxide-(CO),-nitric-oxide-(NOx)- and hydrocarbon-(BSHC)-emissions-are-measured. © 2021 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the International Conference on Advances in Materials Research - 2019.

World University root node

Department of Thermal and Energy Engineering

School of Mechanical Engineering

Vellore Campus

Materials Today: Proceedings

Design optimization of intake manifold of dual fuel engine

Evaluating the improvement in efficiency and heat transfer rate in heat exchangers using additives has been the centre of attraction for many researchers. In this study, a solar flat plate water heater is modelled using ANSYS Fluent, and the simulated results are compared with experimental data. For the simulation, a single-phase model is used with equivalent correlations for the thermo-physical properties of the nanofluid. Using water as the working fluid, the performance was evaluated for a set flow rate and solar insolation. The study is extended by modelling the same in ANSYS Fluent and using water and CuNP mixture as working fluid to analyse the enhancement of heat transfer in thermal absorbers. The pressure drop in the system is analysed and the data is used to justify the usage of nanoparticles in solar thermal absorbers. The efficiency of the system for various volume fractions of nanoparticles is optimized by introducing an efficiency index. © 2021, Springer Nature Singapore Pte Ltd.

Lecture Notes in Mechanical Engineering

Performance Study on Flat Plate Solar Water Heater with Copper Nanoparticles

In this paper, a double-diffusive mixed convection flow in an enclosed cavity with the effects of Soret number (Sr) and Joule’s heating parameter (J) is presented. Finite volume approach-based differed quadratic upstream interpolation for convective kinematics (QUICK) scheme and central difference scheme are used to resolve the respective convective and diffusive fluxes. The results are presented in terms of temperature, concentration and stream line contours by varying the buoyancy ratio (−100 ≤ N ≤ 100), Soret number (Sr = 0 and 1) and Joules number (J = 0 and 1). The present results are validated with the reported literature. Results show that the temperature is uniformly distributed with the absence of Soret number and a bulk fluid diffusion takes place inside the cavity once the Soret effect is induced. The effects of Joules heating on average Nu and Sh are negligible for Sr = 0, and it has a significant variation with Soret number. © 2021, Springer Nature Singapore Pte Ltd.

Effects of Joules Heating and Soret Number on Double-Diffusive Mixed Convection Flow in an Enclosed Square Cavity

Monoclinic ZnWO4 nanostructures with various concentration of Er were prepared by hydrothermal approach. The synthesized nanostructures were characterized by UV–vis spectra, X-ray diffraction (XRD) technique, steady-state and time-resolved fluorescence lifetime measurements. XRD results confirmed that Er3+ ions were successfully incorporated into ZnWO4 lattice without any secondary phase formation. The incorporation and energy transfer of Er into ZnWO4 were revealed by emission spectra and lifetime decay curves. The nonlinear optical properties of the nanostructures were studied by continuous wave Z-scan technique at 532 nm using Nd: YAG laser. From the open aperture and closed aperture Z-scan traces, the extracted nonlinear absorption and refraction data are attributed to reverse saturable absorption and self-defocusing nature of the samples. The optical nonlinearity of the nanostructures was found to be increasing with increased Er3+ dopant concentration. The observed nonlinearity suggests that the synthesized nanostructures could be explored for its applications in advanced photonic devices. © 2019 Elsevier B.V.

Physics

School of Advanced Sciences

Chennai Campus

Journal of Photochemistry and Photobiology A: Chemistry

Luminescence and nonlinear optical properties of Er3+- doped ZnWO4 nanostructures

Cleaner production is a simple defensive mechanism to protect the environment from pollution and depletion of resources. It is also envisioned to minimise the waste and capitalise on natural resources with effective utilization. Solar energy is a natural resource which can be converted into electricity using photovoltaic (PV) system. This article sheds insights on the implementation of solar PV system with interdisciplinary views and analyse motives and barriers for PV adoption by different citizen groups in India. A survey was conducted to understand the people's perception on solar PV energy system and to determine the level of acceptability among the citizens. The survey information was synthesised and consolidated from various perspectives and the result consigns the research findings into technical, human and socio-economic components. The findings were synthesised through cross-cultural, comparative and mixed-method research outcomes by means of Structural Equation Modelling (SEM), Dendrogram diagram and biplot interpretation. Statistical tools such as ‘IBM-SPSS Amos’ and ‘R’ language programming were also used to interpret the results. This article concludes by specifying the barriers that limit the retrofitting interventions, suggests possible measures and policies to overcome such barriers and promote solar energy in India. © 2018 Elsevier Ltd

Language

School of Social Science and Languages

Electrical

School of Electrical Engineering

Journal of Cleaner Production

A sociocultural study on solar photovoltaic energy system in India: Stratification and policy implication

Wind Energy Conversion System (WECS) plays an inevitable role across the world. WECS consist of many components and equipment’s such as turbines, hub assembly, yaw mechanism, electrical machines; power electronics based power conditioning units, protection devices, rotor, blades, main shaft, gear-box, mainframe, transmission systems and etc. These machinery and devices technologies have been developed on gradually and steadily. The electrical machine used to convert mechanical rotational energy into electrical energy is the core of any WECS. Many electrical machines (generator) has been used in WECS, among the generators the Permanent Magnet Synchronous Generators (PMSGs) have gained special focus, been connected with wind farms to become the most desirable due to its enhanced efficiency in power conversion from wind energy turbine. This article provides a review of literatures and highlights the updates, progresses, and revolutionary trends observed in WECS-based PMSGs. The study also compares the geared and direct-driven conversion systems. Further, the classifications of electrical machines that are utilized in WECS are also discussed. The literature review covers the analysis of design aspects by taking various topologies of PMSGs into consideration. In the final sections, the PMSGs are reviewed and compared for further investigations. This review article predominantly emphasizes the conceptual framework that shed insights on the research challenges present in conducting the proposed works such as analysis, suitability, design, and control of PMSGs for WECS.

Department of Software and Systems Engineering

School of Information Technology and Engineering

Department of Communication Engineering

School of Electronics Engineering

Fulltext

Energies

Conceptual Framework of Antecedents to Trends on Permanent Magnet Synchronous Generators for Wind Energy Conversion Systems

Energy plays an important role in a country's economic growth in the current energy scenario, the major problem is depletion of energy sources (non-renewable) are more than being formed. One of the prominent solutions is minimizing the use of fossil fuels by utilization of renewable energy resources. A photovoltaic system is an efficient option in terms of utilizing the solar energy resource. The electricity output produced by the photovoltaic systems depends upon the incident solar radiation. This paper examines the performance simulation of 200KW photovoltaic power system at VIT University, Vellore. The main objective of this paper is to correlate the results between the predicted simulation data and the experimental data. The simulation tool used here is TRNSYS. Using TRNSYS modelling prediction of electricity produced throughout the year can be calculated with the help of TRNSYS weather station. The deviation of the simulated results with the experimented results varies due to the choice of weather station. Results from the field test and simulation results are to be correlated to attain the maximum performance of the system. © 2017 Published under licence by IOP Publishing Ltd.

VIT Unitversity

IOP Conference Series: Materials Science and Engineering

Performance simulation of a grid connected photovoltaic power system using TRNSYS 17

Energy crisis is a prognosis predicted in many cases with the indiscriminate encroachment of conventional energy sources for applications on a massive scale. This prediction, further emboldened by the marked surge in global average temperatures, attributed to climate change and global warming, the necessity to conserve the environment and explore alternate sources of energy is at an all-time high. Despite being among the lead candidates for such sources, solar energy is utilized far from its vast potential possibilities due to predominant economic constraints. Even while there is a growing need for solar panels at more affordable rates, the other options to harness better out of sun's energy is to optimize and improvise existing technology. One such technology is the heat pipe used in Evacuated Tube Collectors (ETC). The applications of heat pipe have been gaining momentum in various fields since its inception and substantial volumes of research have explored optimizing and improving the technology which is proving effective in heat recovery and heat transfer better than conventional systems. This paper carries out a computational analysis on a comparative simulation between two working fluids within heat pipe of same geometry. It further endeavors to study the multiphase transitions within the heat pipe. The work is carried out using ANSYS Fluent with inputs taken from solar data for the location of Vellore, Tamil Nadu. A wickless, gravity-assisted heat pipe (GAHP) is taken for the simulation. Water and ammonia are used as the working fluids for comparative multiphase analysis to arrive at the difference in heat transfer at the condenser section. It is demonstrated that a heat pipe ETC with ammonia as working fluid showed higher heat exchange (temperature difference) as against that of water as working fluid. The multiphase model taken aided in study of phase transitions within both cases and supported the result of ammonia as fluid being a better candidate. © 2017 Published under licence by IOP Publishing Ltd.

Multiphase numerical analysis of heat pipe with different working fluids for solar applications

Pt doped TiO2 nanoparticles with different concentrations of Pt were prepared by sol-gel method. X-ray diffraction (XRD) study reveals that the samples have a homogeneous anatase phase tetragonal system and the lattice parameter analysis indicates that Pt ions substitute into the lattice of TiO2. The addition of dopant increases the growth of TiO2 grains, agglomerates them and shifts the absorption band of TiO2 from ultraviolet to visible region. The incorporation of Pt in TiO2 is also confirmed by fluorescence quenching and the fluorescence lifetime decreases as the volume fraction of Pt dopant increases. Open aperture Z-scan measurements done at 532 nm using 7 ns laser pulses show nonlinear absorption which arises from an effective two photon absorption process. The nonlinear optical properties are characterized by using fluence dependent transmittance measurements in order to reveal the optical limiting effects. It is found that the optical limiting performances of nanoparticles were greatly enhanced with increased concentration of Pt. © 2013 Elsevier Ltd. All rights reserved.

Materials Research Bulletin

Investigation on the structural and nonlinear optical properties of Pt doped TiO2 nanoparticles

This paper presents the numerical investigation of double-diffusive mixed convective flow in an impermeable enclosed cavity. The uniform temperature and concentration is imposed along the vertical walls and the horizontal walls are considered as insulation. The flow behavior is analyzed when the top wall moves left side at a constant velocity (Uo) and the other walls kept remains stationary. Transport equations are solved using finite volume technique. The pressure and velocity terms are coupled by SIMPLE algorithm. The third order deferred Quadratic Upwind Interpolation for Convection Kinematics (QUICK) scheme and second order central difference scheme are applied at the inner and boarder nodal points, respectively. The present numerical simulation is compared with the reported literature and found that are in good agreement. The heat and mass transfer results are presented in the form of iso-temperature and concentration. The Lewis number (Le) and aspect ratio are varied over a wide range to analyse non-dimensional horizontal (U) and vertical velocities (V), stream line contours, temperature and concentration gradients. The present analysis is carried out at constant Prandtl (Pr=0.7), Richardson (Ri=1.0), Darcy (Da=1.0) and Reynolds (Re=100) numbers. Results show that the fluid flow and heat transfer increase with the increase in Lewis Number and low aspect ratio. The local and average Nusselt and Sherwood numbers are also presented for the different Aspect ratio and Lewis number.

WSEAS Transactions on Heat and Mass Transfer

The numerical simulation of double-diffusive laminar mixed convection flow in a lid-driven porous cavity

Solar Parabolic Trough collectors are commonly used to harness the solar power for power generating applications involving high temperatures. In the given paper study we have made use of the SolTrace software which uses the Monte Carlo algorithm for finding out the radiation received on the absorber tube of the collector. The computational study was performed taking into account the solar radiation received at Vellore city in India (12.92oN, 79.13oE) as on 16th February 2013. Further a 3D model of the absorber tube used in the parabolic trough collector was created and meshed with the help of the Ansys Gambit software. The absorber tube which we considered for our study is made up of Stainless Steel AISI 302 material. The meshed model so created was then exported to the Ansys Fluent 6.3 software and simulations were performed for different mass flow rates of the fluid. The fluid which we used in the computational analysis study is Therminol 55. The temperature differences for different mass flow rates of the liquid passing through the absorber tube were found out and based on the temperature rise contours plots so obtained, we have plotted the surface heat transfer coefficient for the absorber tube. We also found out the static temperature contour plot for the fluid flowing through the given absorber tube taking into account the heat flux acting on the absorber tube due to the hourly and daily average solar radiation.

Applied Mechanics and Materials

Computational Study on Estimating the Surface Heat Transfer Coefficient of Absorber Tube in Solar Parabolic Trough Collector

In this work the effect of swirl is analysed in a 3 - dimensional convergent divergent supersonic nozzle on the shock structure under various back pressure conditions. The numerical analysis is carried out in a three dimensional flow field using commercial CFD tool. The three dimensional supersonic convergent divergent (CD) nozzle is modelled in ICEMCFD and the domain is discretized using hexahedral elements. The flow field through the CD nozzle is obtained by solving the governing equations namely continuity, momentum and energy equations by Finite volume discretization using commercial CFD code ANSYS FLUENT 12.0. Turbulence is taken care by shear stress transport SST - K- ω mode of closure. It was found that the effects of swirl and nozzle back pressure weaken the strength of shock -structure considerably. Increasing the back pressure influence the shock to move upstream towards throat in the divergent portion, whereas swirl stretches the shock structure axially downstream to the throat and weakens the shock strength. © Research India Publications.