Conference Papers
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Item Computation of incompressible fluid flows in a single-sided cross-shaped lid-driven cavity using Lattice Boltzmann method(Institute of Electrical and Electronics Engineers Inc., 2017) Bhopalam, R.; Arumuga Perumal, D.A.This work is an application of a novel Scientfic Computational algorithm, namely, Lattice Boltzmann method (LBM), which has recently been recognized due to two prominent features of its algorithm - simplicity and ability to be parallelized. To get an overview of its application, this study implements LBM with Single Relaxation time (SRT) model to compute the steady incompressible fluid flows in a single sided cross-shaped lid-driven cavity (SSC-LDC). Being categorized as a complex planar geometry of the lid-driven cavity, the code validation for this work is performed by comparing the results of a single sided lid driven cavity (SS - LDC) with benchmarks. The streamline patterns and centerline velocity profiles compared with published results are found to be in good accordance. After establishing the reliability of the code, the mathematical code is extended to simulate the fluid flow in the single-sided cross-shaped lid-driven cavity (SSC-LDC). To demonstrate the physical sense of the flows in SSC-LDC, the development and progress of primary and secondary vortices have also been well captured with the variation of Reynolds number. © 2016 IEEE.Item Lattice Boltzmann computation of two dimensional differentailly heated cavity of incompressible fluid with different aspect ratios(Institute of Electrical and Electronics Engineers Inc., 2017) Karki, P.; Yadav, A.K.; Arumuga Perumal, D.A.Lattice Boltzmann Method (LBM) is a novel computational technique to solve fluid flow problem in bounded domain. Continuum based methods are being widely used to solve the natural convection problem, whereas in the last two decades, mesoscopic approach has gained popularity to solve heat transfer and fluid flow problems. In natural convection cavity, density difference caused by heating and cooling of fluid at different locations gives rise to buoyancy force which in turn drives the fluid flow. The right side and left side wall of the cavity is made hot and cold respectively whereas top and bottom walls are made adiabatic. In the present work, natural convection problem of differently heated cavity with constant Prandtl number (Pr = 0.71) and varying Rayleigh number (Ra =103-106) is solved employing LBM to study the effect of various aspect ratios (H/L) on both Nusselt number and streamlines. Results are plotted in the form of streamlines and isotherms for different Rayleigh numbers at different aspect ratios. Nusselt numbers are obtained at the hot wall and cold wall to study the rate of heat transfer. Obtained results are compared with the existing results. It is found that with increase of Rayleigh number, there is increase in the Nusselt number. The increment in aspect ratio leads to the significant decrement in the Nusselt number and vice versa. © 2017 IEEE.Item Experimental and numerical investigation on conjugate effects in deep parallel microchannel using tio2 nanofluid for electronic cooling(Dalian University of Technology, 2018) Narendran, G.; Gnanasekaran, N.; Arumuga Perumal, D.A.The present study reports the numerical investigation of laminar forced convection based on TiO2 nanofluid in a rectangular copper microchannel surrounded by Aluminium block to examine the cooling effects for increased flow rates and particle concentration. The analysis involves the use of pure fluid and TiO2 nanofluid with the volume fractions of 0.01, 0.15, 0.20 and 0.25% for different flow rates. The study also examines the influence of conjugate heat transfer behavior of the microchannel using commercially available software FLUENT-15. © 2018 by the authors of the abstracts.Item Numerical simulation of microgap based focal brain cooling bioimplants for treatment of epilepsy(Dalian University of Technology, 2018) Narendran, G.; Kumar, A.; Gnanasekaran, N.; Arumuga Perumal, D.A.Epilepsy is most common neurological disorder that affects people of all ages and around 30% of the patients do not recover because of existing treatment like medication therapy and surgery. Due to imprudent neuronal activities, excessive heat is observed at epileptic focus and to cool this focal cerebral cooling system is used. Our aim of this study is to enhance the existing design of focal cerebral cooling system by adding constructional structures there by creating micro gaps throughout the cooling device. In this study computational model is developed to perform transient analysis on flow hydrodynamics and heat transfer using commercial package ANSYS FLUENT 15.0. © 2018 by the authors of the abstracts.Item Lattice Boltzmann computation of creeping fluid flow in roll-coating applications(American Institute of Physics Inc. subs@aip.org, 2018) Rajan, I.; Kesana, B.; Arumuga Perumal, D.A.Lattice Boltzmann Method (LBM) has advanced as a class of Computational Fluid Dynamics (CFD) methods used to solve complex fluid systems and heat transfer problems. It has ever-increasingly attracted the interest of researchers in computational physics to solve challenging problems of industrial and academic importance. In this current study, LBM is applied to simulate the creeping fluid flow phenomena commonly encountered in manufacturing technologies. In particular, we apply this novel method to simulate the fluid flow phenomena associated with the "meniscus roll coating" application. This prevalent industrial problem encountered in polymer processing and thin film coating applications is modelled as standard lid-driven cavity problem to which creeping flow analysis is applied. This incompressible viscous flow problem is studied in various speed ratios, the ratio of upper to lower lid speed in two different configurations of lid movement - parallel and anti-parallel wall motion. The flow exhibits interesting patterns which will help in design of roll coaters. © 2018 Author(s).Item Flow induced hotspot migration studies with heat spreader integrated microchannels using reduced graphene oxide nanofluids(Institute of Electrical and Electronics Engineers Inc., 2018) Narendran, G.; Gnanasekaran, N.; Arumuga Perumal, D.A.The present study involves experimental and numerical investigations of laminar forced convection in parallel microchannel heat sink accompanied with heat spreader of size 30 mm2. Water and reduced graphene oxide nanofluid of 0.07-0.12 vf % is used as working fluid. The numerical study is performed by incorporating the thermo physical properties of reduced graphene oxide nanofluid for different Reynolds number (Re) ranging from 150 to 360 for a constant heat flux of 35 W/cm2. Additionally, studies on migration of hotspot with heat spreader from the bottom of the heat sink under varying Reynolds number are also discussed. © 2018 IEEE.Item Entropy generation study of TiO2 nanofluid in microchannel heat sink for Electronic cooling application(Institute of Physics Publishing helen.craven@iop.org, 2018) Kumar, A.; Narendran, G.; Arumuga Perumal, D.A.Development of Micro-electro-mechanical systems (MEMS) in the recent years has motivated and necessitated the study of flows in micro-scale geometries such as microchannel. Thermal management in ultra-densely packed electronic devices is highly essential to increase the reliability of the component without compromising packaging. The present study provides an experimental and numerical investigation on laminar forced convection in parallel microchannel heat sink accompanied with integrated Aluminium bulk heat spreader and ultrafine TiO2 nanoparticle based nanofluid for different wt. % ranging from 0.1-0.35 under different power ratings. Numerical study is performed to understand the flow hydrodynamics in microchannel to investigate the temperature distribution in bulk heat spreader with increased flow rates by implementing the thermo-physical properties. Furthermore, a study on Exergy and entropy generation for different fluids is also discussed. The experimental studies reveal that parallel microchannel increases the effectiveness of integrated cooling with a marginal temperature deviation between the heat sink and Aluminium bulk for a distance of 1.5 mm. Implementation of TiO2 nanofluid registered as a better working fluid than the pure fluid for all the experimental settings. © Published under licence by IOP Publishing Ltd.Item Numerical Studies for Charging and Discharging Characteristics of Composite Phase Change Material in A Deep and Shallow Rectangular Enclosure(Institute of Physics Publishing helen.craven@iop.org, 2018) Chavan, S.; Arumuga Perumal, D.A.; Gumtapure, V.In this study, a numerical analysis of the melting process with natural convection in a rectangular enclosure has been performed using enthalpy porosity model. A Composite phase change material (Paraffin wax (98%) is used as base material and copper nanoparticles (2%) as additives) is used. The enclosure is heated from one side and opposite side is isothermal at 300 K, and remaining walls are thermally insulated. Melting heat transfer in a rectangular enclosure with different orientations are investigated numerically. The flow field results in nonuniform melting of the composite phase change material (CPCM). The interface morphology is used to infer flow structure and the extent of two-dimensional energy transport. These flow patterns are found to be dependent on the orientation and the initial CPCM sub-cooling. The results reveal that the enclosure orientation has a significant effect on the formation of natural convection currents and consequently on the heat transfer rate and melting time of the CPCM. As the orientation changed from deep to shallow, the convection currents in the enclosure, increases and chaotic flow structure appear. Hence, it can be concluded that the heat transfer enhancement ratio for the deep enclosure is more than that of the shallow enclosure. © Published under licence by IOP Publishing Ltd.Item Application of Lattice Boltzmann Method for fluid flow modelling of FSLDR domain(Elsevier Ltd, 2019) Bhatt, T.; Arumuga Perumal, D.A.In this work Lattice Boltzmann method is used to solve the Four Sided lid-driven rectangular cavity flow (FSLDR) problem. The fluid is considered as incompressible. In the present problem all the four walls moves with a constant velocity. The left wall moves in positive y-direction, the right wall moves in negative y-direction. The top wall moves in positive x-direction and the bottom wall moves in negative x-direction. The aspect ratio of the cavity taken is 0.50. The present code is validated for single lid-driven cavity flow problem. Next, the study is extended to FSLSR problem. The position of vortex obtained are studied at Reynolds number Re=50, 100, 500, 1000. In addition to the primary vortex, two secondary vortices are also obtained. Thus, the present study shows that Lattice Boltzmann Method can be used to capture the details of vortex dynamics © 2019 Elsevier Ltd.Item LBM combined with LM algorithm to estimate the unknown heat flux - A new inverse approach(Elsevier Ltd, 2019) Kumar, D.; Arumuga Perumal, D.A.; Gnanasekaran, N.; Kumar, M.K.The objective of the present work is the application of the Levenberg-Marquardt method as an inverse method for the estimation of the heat flux. In this paper inverse estimation of heat flux for a two-dimensional heat conduction problem is carried out. As a direct method, in the first attempt the solution of two-dimensional inverse heat conduction problem is formulated by using Lattice Boltzmann Method as a forward model. Later the solution to the problem is also obtained by using Finite Difference Method (FDM) as the forward model for the purpose of validation. Once the forward model is established, Levenberg-Marquardt Method is used as an inverse model to estimate the input parameter i.e. heat flux which is reported. A complete error analysis of inverse model with known values is performed. As the Lattice Boltzmann Method (LBM) is acclimatizing to parallel computation, its use is recommended in Levenberg-Marquardt method for the solution of inverse heat conduction problem which is evident from the results. © 2019 Elsevier Ltd.