Faculty Publications

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    Lattice boltzmann simulation of double-sided deep cavities at low reynolds number
    (Pleiades journals, 2019) Kesana, B.; Shetty, V.V.; Arumuga Perumal, D.A.
    Lattice Boltzmann method (LBM) has been created as an option computational technique conversely with conventional computational fluid dynamics (CFD) strategies. In the present work, the fluid flow of the two-dimensional low Reynolds number flow in a rectangular cavity with two opposite moving lids and different aspect ratios (depth-to-width ratios) is examined using LBM. The impacts of aspect ratio shifting from 1.2 to 10 on vortex structure in the cavity were watched. The streamline patterns were displayed in detail. As the perspective proportion is steadily expanded from 1.2, the stream structure creates the longitudinal way of the cavity and the quantity of vortices step by step increments with the expanding viewpoint proportion. The advancement of bigger external vortices is from the centre of the cavity and observed stream patterns were symmetric about the cavity centre at various proportion. © Springer Nature Singapore Pte Ltd. 2019.
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    Computational Modelling of Bioheat Transfer for Hyperthermia Using Finite Difference Method
    (Springer Science and Business Media Deutschland GmbH, 2023) Hegde, T.; Maniyeri, R.
    Bioheat transfer is a field which involves the study of thermal energy in living systems like tissues. Penne’s bioheat transfer equation is a popular model used in this field. The objective of this study is to develop a computational model to understand the effect of different heating methods like magnetic hyperthermia and laser treatment for living tissues with an embedded tumour. This is done by solving Penne’s bioheat transfer equation using finite difference method for a two-dimensional domain. Initially, Penne’s model in its one-dimensional form is used to observe heat transfer in a living tissue. After validating the results, the model is extended to a two-dimensional domain with an embedded tumour. The properties of the healthy tissue and the tumour cells are considered to be different. Using different heating methods, the temperature of the tumour is raised to 40–43 ℃ to damage the tumour cells, and the time taken for necrosis is found. The results obtained will be useful for tumour detection and also its treatment. © 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.
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    Numerical Study of PCM-Based Energy Storage System Using Finite Difference Method
    (Springer Science and Business Media Deutschland GmbH, 2024) Abhijith, C.; Maniyeri, R.
    Energy storage systems incorporating phase change material (PCM) are becoming the answer to intermittent energy availability in the area of solar cooking vessels and solar room heating systems. These thermal energy storage systems are efficient, reliable and can reduce running costs and investments. The present work investigates the melting of n-octadecane using enthalpy formulation method by using finite difference method-based discretization. Accordingly, a numerical model is developed in MATLAB which is validated first by comparing with previous works. Further using the developed model studies on wall materials, thickness, different PCMs and temperatures are carried out. It is found that metal containers with higher thermal conductivities provided significant boost in energy storage. The increased thickness of walls adds significant change only if containers are of lower thermal conductivity such as steel. Different PCMs are analysed, and their operating temperature and energy storage capabilities are studied. In addition, enthalpy equation in cylindrical coordinates is solved since practical PCM storages are commonly cylindrical in shape. At the end, the numerical results are compared with an experimental case with paraffin wax as PCM. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd 2024.
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    Numerical Modeling of Skin Bioheat Transfer Using Finite Difference Method
    (Springer Science and Business Media Deutschland GmbH, 2024) Naveen Reddy, D.; Spandana Bhat, K.; Rajesh, P.; Krishna Kishore, R.; Abhiram, C.; Maniyeri, R.
    Skin bioheat transfer is heat transfer in the cross-section of the skin tissue. Pennes bioheat transfer equation is the basis of skin bioheat transfer. Finite difference implicit-based methodology is used for solving Pennes bioheat transfer equations. The numerical simulations are performed for one-dimensional and two-dimensional skin models with various heat sources, blood perfusion rates, and different parameters. Both steady and transient state equations for one-dimensional skin are analyzed by considering various cases like spatial heating, step heating, and constant surface heating for which temperature distribution over the cross-section of skin is plotted and results are validated. With solar radiation as the source of energy, simulation the maximum time of exposure of skin to solar radiation above which it is prone to sunstroke at a particular location is found to be around four minutes. For two-dimensional skin tissue the transient study for different heat sources like sinusoidal heat source, laser heat source, constant surface heating, point heat source for five different skin models is done and analyzed. A detailed study on cooling techniques is done for three different cooling conditions to find the best cooling method and concludes that ice cooling is better than others. Skin treatment for treating tumors by keeping the tumor tissue at a constant higher temperature which is also known as hyperthermia is studied. Also, the effect of sweating for skin tissue which is exposed to dissipated heat by an electronic chip is studied. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2024.
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    Uniformly-Convergent Numerical Methods for a System of Coupled Singularly Perturbed Convection-Diffusion Equations with Mixed Type Boundary Conditions
    (Taylor and Francis Ltd., 2013) Mythili Priyadharshini, R.M.; Ramanujam, N.
    In this paper, two hybrid difference schemes on the Shishkin mesh are constructed for solving a weakly coupled system of two singularly perturbed convection - diffusion second order ordinary differential equations subject to the mixed type boundary conditions. We prove that the method has almost second order convergence in the supremum norm independent of the diffusion parameter. Error bounds for the numerical solution and also the numerical derivative are established. Numerical results are provided to illustrate the theoretical results. © 2013 Vilnius Gediminas Technical University, 2013.
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    Reduction of carbon emission by enhancing energy efficiency of forced draft fans in thermal power plants
    (Acta Press journals@actapress.com, 2014) Mandi, R.P.; Yaragatti, R.Y.
    In this paper, various techno-economical feasible methods for reducing the carbon emission by enhancing the energy efficiency of forced draft (FD) fans in coal-fired thermal power plants based on the energy audit study conducted in 28 numbers of 210MW power plants in India are discussed. The best operating points for pressure gain, flow, pressure drop, equipment efficiency, power input and specific energy consumption are simulated by using MATLAB, and presented in this paper with case study to validate the results. Optimizing the pressure at FD fan discharge and maintaining the optimum secondary air pressure at windbox will enhance the combustion characteristics. Operational optimization and control of excess air will reduce the auxiliary power of FD fans. Optimum sizing of FD fans and motors will reduce the auxiliary power by 0.10% gross energy generation and reduce the CO2 emission by 1,600 t/year.
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    Entrance Region Flow in Concentric Annuli with Rotating Inner Wall for Herschel–Bulkley Fluids
    (Springer, 2015) Kandasamy, A.; Nadiminti, S.R.
    A finite difference analysis of the entrance region flow of Herschel–Bulkley fluids in concentric annuli with rotating inner wall has been carried out. The analysis is made for simultaneously developing hydrodynamic boundary layer in concentric annuli with the inner cylinder assumed to be rotating with a constant angular velocity and the outer cylinder being stationary. A finite difference analysis is used to obtain the velocity distributions and pressure variations along the radial direction. With the Prandtl boundary layer assumptions, the continuity and momentum equations are solved iteratively using a finite difference method. Computational results are obtained for various non-Newtonian flow parameters and geometrical considerations. A significant asymmetry is found in the entrance region which is gradually reduced as the flow develops. For smaller values of aspect ratio and higher values of Herschel–Bulkley number the flow is found to stabilize more gradually. Comparison of the present results with the results available in literature for various particular cases has been done and found to be in agreement. © 2015, Springer India Pvt. Ltd.
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    Entrance region flow heat transfer in concentric annuli with rotating inner wall for bingham fluid
    (Budapest University of Technology and Economics office@pp.bme.hu Budafoki ut 4 Budapest H-1111, 2016) Nadiminti, S.R.; Kandasamy, A.
    A finite difference analysis of the entrance region flow heat transfer of Bingham fluid in concentric annuli with rotating inner wall has been carried out. The analysis is made for simultaneously developing hydrodynamic and thermal boundary layer in concentric annuli with one wall being isothermal and other one being adiabatic. The inner cylinder is assumed to be rotating with a constant angular velocity and the outer cylinder being stationary. A finite difference analysis is used to obtain the velocity distributions, pressure drop and temperature variations along the radial direction. Computational results are obtained for various values of aspect ratio N, Bingham number B and Prandtl's number. Comparison of the present results with the results available in literature for various particular cases has been done and found to be in agreement.