Conference Papers

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    Chassis mounted single stage impulse turbine for wind energy harvesting on a cruising transport vehicle
    (Institute of Electrical and Electronics Engineers Inc., 2016) Hegde, S.S.; Thamban, A.; Ahmed, A.; Arun, M.
    Fossil fuels have been a means of energy source since a long time, and have tended to the needs of the large global population. These conventional sources are bound to deplete in the near future and hence there is a need for producing energy from renewable energy sources like solar, wind, geothermal, tidal etc. Technologies involving renewable energy are a growing subject of concern. The problem is the excessive pollution caused by conventional sources of energy and their impact on the environment. In particular, one of the main sources of pollution is harmful gases emitting out of automobiles. Wind energy is one among the renewable energy sources which is implemented in large scale energy production. A large amount of research has been done in this field to harness energy and power houses and other amenities are nearby wind farms. The purpose of this study is to consider the use of wind energy along with conventional energy sources to power automobiles. Specifically the concept of an impulse turbine mounted on the chassis of a typical vehicle structure is considered. Computational Fluid Dynamics (CFD) is used to validate the concept and also come up with a design that maximizes energy generation by such turbines. © 2015 IEEE.
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    A study of influence of material properties on magnetic flux density induced in magneto rheological damper through finite element analysis
    (EDP Sciences edps@edpsciences.com, 2018) Gurubasavaraju, T.M.; Kumar, K.; Arun, M.
    Magnetorheological fluids are smart materials, which are responsive to the external stimulus and changes their rheological properties. The damper performance (damping force) is dependent on the magnetic flux density induced at the annular gap. Magnetic flux density developed at fluid flow gap of MR damper due to external applied current is also dependent on materials properties of components of MR damper (such as piston head, outer cylinder and piston rod). The present paper discus about the influence of different materials selected for components of the MR damper on magnetic effect using magnetostatic analysis. Different materials such as magnetic and low carbon steels are considered for piston head of the MR damper and magnetic flux density induced at fluid flow gap (filled with MR fluid) is computed for different DC current applied to the electromagnetic coil. Developed magnetic flux is used for calculating the damper force using analytical method for each case. The low carbon steel has higher magnetic permeability hence maximum magnetic flux could pass through the piston head, which leads to higher value of magnetic effect induction at the annular gap. From the analysis results it is observed that the magnetic steel and low carbon steel piston head provided maximum magnetic flux density. Eventually the higher damping force can be observed for same case. © The Authors, published by EDP Sciences, 2018.
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    Estimation of interfacial heat transfer coefficient for horizontal directional solidification of Sn-5wt%pb alloy using genetic algorithm as inverse method
    (Springer Verlag, 2019) Vishweshwara, P.S.; Gnanasekaran, N.; Arun, M.
    In the present work, a one-dimensional transient solidification heat transfer problem is solved to determine the unknown interfacial heat transfer coefficient (IHTC) at the mold–metal interface using genetic algorithm (GA), an evolutionary and widely known algorithm, as an inverse method. The forward model is numerically solved to obtain the exact temperatures by incorporating the appropriate correlation for the IHTC that varies with time. In order to mimic experiments, the exact temperatures are then perturbed with the standard deviations of 0.01, 0.02, and 0.03. In the inverse estimation, genetic algorithm is used to minimize the objective function, thereby reducing the error between the measured and the simulated temperatures. The study on the performance parameters of the algorithm is also discussed in detail. © Springer Nature Singapore Pte Ltd. 2019.
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    A novel framework for the estimation of interfacial heat transfer coefficient using Bat algorithm during solidification of metal casting
    (Toronto Metropolitan University, 2019) Vishweshwara, P.S.; Gnanasekaran, N.; Arun, M.
    In the present work, the interfacial heat transfer coefficient (IHTC) at the mold metal interface is estimated during solidification of Al-4.5wt%Cu alloy using ANN-Bat-Bayesian framework. The forward model comprises of a one dimensional transient governing equation for the solidification of metal casting and is solved using explicit finite difference scheme with the available IHTC correlation from the literature. Within the range of values of constants of IHTC correlation, a set of numerical simulation is performed and corresponding temperature output is trained using Artificial Neural Network (ANN). The network created acts a fast forward model replacing the FDM scheme during IHTC estimation thus reducing computational time. Bat algorithm is used as inverse method along with the Bayesian framework, that drives towards the accurate retrieval of unknown parameters. © 2019, Toronto Metropolitan University. All rights reserved.
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    Effect of magnetic permeability, shearing length, and shear gap on magnetic flux density of the magnetorheological damper through finite element analysis
    (Elsevier Ltd, 2020) Kumar Kariganaur, A.; Kumar, H.; Arun, M.
    The performance of the magnetorheological (MR) damper is determined based on the damping force of the damper which is used to reduce the unwanted vibrations in the automobile suspension system. In this study, an axisymmetric magnetorheological damper model is analyzed using ANSYS finite element (FE) analysis to simulate a distribution of magnetic field in the fluid flow region. Firstly, the materials used for the fabrication of MR damper such as SA1018 and Aluminium are used for the permeability analysis for applied current in shear mode operation. It is evident from the result that, a material with higher magnetic permeability (SA1018) gives higher magnetic flux density in the fluid flow gap. By using SA1018 material for further study the effect of increase in shear gap and shearing length of the MR damper, there is a exponential decay in the magnetic flux density in the flow gap. And finally, by using the response surface methodology optimum values are obtained for maximum magnetic flux density. © 2020 Elsevier Ltd. All rights reserved.
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    Numerical Instability Assessment of Natural Circulation Loop Subjected to Different Heating Conditions
    (Springer Science and Business Media Deutschland GmbH, 2022) Thimmaiah, S.; Wahidi, T.; Yadav, A.K.; Arun, M.
    Natural circulation loop (NCL) is a passive system in which the driving action of the buoyancy force establishes fluid circulation by overcoming the frictional force without the help of any external power source. NCLs are prone to several kinds of instabilities due to the nonlinearity of the natural convection process. In fact, it is an inability of NCLs to sustain themselves against small perturbations to which any physical system is subjected. This instability in fluid flow creates flow oscillation, chaotic non-linear dynamic behaviour and flow reversal. In this article, three-dimensional computational fluid dynamics (CFD) numerical simulations have been carried out for a range of supercritical pressures (80 bar to100 bar) and heat inputs (250 W to 2500 W) to do the comparative investigation of instability phenomenon in supercritical CO2-based regular natural circulation loop configured with two different types of heat sources, i.e. heater and isothermal wall at the source with a cold heat exchanger (CHX) at sink. Results show higher instabilities for heater-exchanger loop (Heater-CHX) than an isothermal heater with heat-exchanger loop (ISO-CHX). With an increase in heat input, loops attain stability at a faster rate for a given operating pressure. At a lower heat input, both the loops show bidirectional fluctuation, whereas it is unidirectional at high heat input. Nusselt number shows that the Heater-CHX loop’s heat transfer capability is more compared to ISO-CHX loops. Obtained results are validated with the existing correlations, and a good agreement is obtained. © 2022, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.