Faculty Publications
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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 Analysis of functionally graded metal foams for the accomplishment of heat transfer enhancement under partially filled condition in a heat exchanger(Elsevier Ltd, 2023) Jadhav, P.H.; Gnanasekaran, N.; Mobedi, M.The use of partially filled high porosity graded aluminum and copper foams is explored to satisfy both heat transfer and pressure drop in a heat exchanger. Both positive and negative orientations are accomplished for the enhancement of heat transfer with reduction in the pressure drop. The present research includes three different configurations M1, M2 and M3 (porous layer inner diameter = 0.06 m, 0.04 m, and 0.02 m, respectively, while outer diameter = 0.10 m) partially filled with positive (i.e., increasing, 20/45 PPI) negative (i.e., decreasing, 45/20 PPI) and compound (i.e., 45 Cu/20 Al PPI) graded porous layer thickness. Each configuration involves three different graded porous layer to present the optimum graded porous layer thickness. The thermo-hydrodynamic characteristics are apprehended by using Darcy Extended Forchheimer (DEF) flow and local thermal non-equilibrium (LTNE) models for the partially filled graded porous structure and k-ω turbulence model is accomplished in open passage flow of the conduit. The decreasing graded foam located inside the models M1 and M2 performed 1.68%–12.85% and 13.42%–23.32% higher heat transfer rate compared to without graded metal foam of models M2 and M3, respectively accompanied with 55.43%–84.02% and 35.69%–50.31% lesser pumping power. © 2022 Elsevier LtdItem Numerical analysis of thermo hydro-dynamics behavior of solar flat plate collector with square and V-cut twisted tape inserts(Taylor and Francis Ltd., 2025) Narendran, G.; Jadhav, P.H.; Gnanasekaran, N.Numerical analysis has been conducted for a solar collector with two circular pipes having semi-circular contact with absorber plate. The tubes are analyzed with and without the inclusion of twisted tape inserts of twist ratio Y = 3 and Y = 4. The comparison between the heat transfer and pressure drop characteristics of a plain tube to that fitted with the twisted tape inserts is done and validated against experimental results with good agreement. Additionally, helical twisted tape is modeled with square- and V-cut to analyze its influence on flow and heat transfer phenomenon. V-cut twisted tape inserts act as turbulence promoters, increasing fluid flow and inducing vortex-like motion. As a result, boundary layer around the absorber plate is disrupted with decrease in stagnation temperature, resulting in better heat transfer and more effective absorption and conversion of solar energy. The Nusselt number, friction factor, and heat transfer coefficient variation with the Reynolds number have been studied for the given heat fluxes. It is found that the Nusselt number of the fluid flowing in the plain tube is increased by 76.44% when the tube is fitted with twisted tape inserts. The pressure drop in the tube is found to increase with the presence of the twisted tapes. The average temperature along the length of the circular tube and absorber plate has also been reported. © 2023 Taylor & Francis Group, LLC.