Faculty Publications
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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 Forced Convection Analysis in a Horizontal Pipe in the Presence of Aluminium Metal Foam—A Numerical Study(Springer Science and Business Media Deutschland GmbH, 2021) Jadhav, P.H.; Kotresha, B.; Gnanasekaran, N.; Arumuga Perumal, D.Numerical exploration of forced convective heat transfer through the aluminium metallic foam filled in a horizontal pipe is done expending a commercially existing software ANSYS FLUENT 15.0. The motive of the ongoing numerical examination is to investigate the effect of fully filled metal foam in a horizontal pipe for different flow regimes. 10 PPI metal foam having 0.85 porosity is filled 60% along the length of pipe in the flow direction. The Darcy-extended Forchheimer (DEF) flow and local thermal non-equilibrium (LTNE) models are considered at the metal foam region to envisage fluid flow and augment in heat transfer. The numerical methodology is validated by comparing the results with available experimental data. The results of pressure loss, variation of wall temperature and Nusselt number are reported and discussed. © 2021, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.Item Thermodynamic analysis of entropy generation in a horizontal pipe filled with high porosity metal foams(Elsevier Ltd, 2022) Jadhav, P.H.; Gnanasekaran, N.; Arumuga Perumal, D.A.In the field of thermal management of electronic equipment, examining entropy generation properties is extremely useful. The entropy production experiments have been expanded to porous media using high porosity metal foams. The entropy production/generation for forced convection heat transfer in a tube is quantified via a numerical research. In the field of air stream direction, the horizontal pipe is entirely filled with nickel metal foam of 0.6 m length. For the isotropic porous metal foam zone, the Darcy-extended Forchheimer (DEF) flow is used to capture the dynamics of flow and local thermal non-equilibrium (LTNE) model is used for analyzing the heat transport phenomenon, while the k-e turbulent model is used for the non-foam porous region of the tube. The effect of fully filled nickel metallic foam with different pore densities of 10, 20, and 30 metal foam with a porosity of 0.85 is being investigated. The computational solutions presented here are supported by experimental results published in the literature. The outlet exergy of the system rises with higher flow rates and falls with higher metal foam pore densities. The results of entropy generation due to thermal and fluid friction and Bejan number conceptions are also shown and discussed. © 2022 Elsevier Ltd.Item Performance Evaluation of Single Pass Solar Air Heater with Stepped-Type Arrangement of Metal Foam by a Numerical Study(Springer Science and Business Media Deutschland GmbH, 2024) Diganjit, R.; Gnanasekaran, N.A solar air heater is easy to build and easy to use for drying applications, room heating purposes, etc. In the present study, single-pass forced convection rectangular-type solar air heater is studied numerically. The copper metal foam with 0.92 porosity is used for case (a) empty channel, cases (b) to (e) comprising of different stepped-type arrangements, and case (f) fully filled metal foam condition and studied numerically to obtain outlet temperature, pressure drop and the performance factor of the solar air heater. The Reynolds number is varied from 4401 to 5868. Based on this range of Reynolds number RNG k-ε model with enhanced wall function is adopted for numerical simulations. The local thermal equilibrium model is used to simulate the porous zone. The Rosseland radiation model has been chosen with solar ray tracing method. The case (c) is the best stepped-type arrangement to get same outlet temperature compared to fully filled metal foam case (f). Hence, the material cost is minimized. The temperature rise is 8.89% more compared to empty channel solar air heater. Case (c) has less pressure drop compared to other metal foam arrangements. The performance factor for case (c) is 2.03. © 2024, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.Item Numerical consideration of LTNE and darcy extended forchheimer models for the analysis of forced convection in a horizontal pipe in the presence of metal foam(American Society of Mechanical Engineers (ASME), 2021) Jadhav, P.H.; Gnanasekaran, N.; Arumuga Perumal, D.The intent of the current research work is to emphasize the computational modeling of forced convection heat dissipation in the presence of high porosity and thermal conductivity metallic foam in a horizontal pipe for different regimes of the fluid flow for a range of Reynolds number. A two-dimensional physical domain is considered in which Darcy extended Forchheimer (DEF) model is adopted in the aluminum metallic foam to predict the features of fluid flow and local thermal nonequilibrium (LTNE) model is employed for the analysis of heat transfer in a horizontal pipe for different flow regimes. The numerical results are initially matched with experimental and analytical results for the purpose of validation. The average Nusselt number for fully filled foam is found to be higher compared to other filling rate of metallic foams and the clear pipe at the cost of pressure drop. As an important finding, it has been observed that the laminar and transition flow gives higher heat transfer enhancement ratio and thermal performance factor compared to turbulent flow. This work resembles numerous industrial applications such as solar collectors, heat exchangers, electronic cooling, and microporous heat exchangers. The novelty of the work is the selection of suitable flow and thermal models in order to clearly assimilate the flow and heat transfer in metallic foam. The presence of aluminum metal foam is highlighted for the augmentation of heat dissipation in terms of PPI and porosity. The parametric study proposed in this work surrogates the complexity and cost involved in developing an expensive experimental setup. © 2021 American Society of Mechanical Engineers (ASME). All rights reserved.Item Performance score based multi-objective optimization for thermal design of partially filled high porosity metal foam pipes under forced convection(Elsevier Ltd, 2022) Jadhav, P.H.; Trilok, G.; Gnanasekaran, N.; Mobedi, M.Optimization study in flow through metal foams for heat exchanging applications is very much essential as it involves variety of fluid flow and structural properties. Moreover, the identification of best combinations of structural parameters of metal foams for simultaneous improvement of heat transfer and pressure drop is a pressing situation. In this work, six different metal foam configurations are considered for the enhancement of heat transfer in a circular conduit. The foam is aluminum with PPI varying from 10 to 45 and almost the same porosity (0.90-0.95). The aluminum foams are chosen from the available literature and they are partially filled in the conduit to reduce the pressure drop. For a constant heat flux condition, the goal is to find out the efficient metal foam and configurations when air is considered as a working fluid. A special attention is paid to the preference between pressure drop and heat transfer enhancements. That is why TOPSIS optimization techniques with five different criteria (contains the combination of the weightage/priority of heat transfer and pressure drop) is used. Based on the numerical results of heat and fluid flow in conduit, it is found that when an equal importance is given to both heat transfer and friction effect, 30 PPI aluminum foam with 80% filling on the inner lateral of the pipe provides the best score as 0.8197. The best configuration and PPI for different preferences between friction and heat transfer enhancements is discussed in details. The Reynolds number varies from 4500 to 16500. © 2021 Elsevier LtdItem Numerical assessment of thermal characteristics of metal foams of orderly varied pore density and porosity under different convection regimes(Elsevier Masson s.r.l., 2022) Trilok, G.; Kumar, K.K.; Gnanasekaran, N.; Mobedi, M.The present study is done to analyze heat transfer and fluid flow in a channel with orderly varied pore density and porosity combination of foam samples. Darcy Forchheimer flow and LTNE thermal models are considered to estimate heat transfer characteristics. Considering the effect of orderly varied combinations of the dual structural properties, forced convection over a range of flow velocities and natural convection phenomenon are studied numerically in the channel housing porous samples. Two limiting solutions for Nusselt number (Nu) i.e., Nun (for natural convection) and Nuf (for forced convection) for Ri→∞ and Ri→0 respectively, as a function of independent variable Richardson number (Ri) with structural properties pore density and porosity are obtained with the help of local thermal non-equilibrium (LTNE) thermal model and Darcy-Forchheimer flow model. Further these asymptotic solutions are blended using technique illustrated in the literature in order to obtain solution for Nusselt number for mixed convection (Num). Correlations for Nusselt number as a function of combination of porosity and pore density are obtained emphasizing on the varied significance of these parameters in different convection regime. The present study not only emphasizes on effect of combination of structural properties of metal foams on heat transfer characteristics, but also illustrates a technique that enables to arrive at suitable correlation for an intermediate phenomenon existing between two other extremes, with zero computational cost. Effect of pore density on heat transfer characteristics at a given porosity, is found to be not much influencing in natural convection dominant regime. However, in mixed and forced convection dominant scenario it is illustrated that, effect of variation in pore density and porosity plays a significant role in expressing distinguishable heat transfer characteristics, along with other well-known independent parameters such as porosity and Reynolds number. © 2021 Elsevier Masson SAS