Banjara Kotresha

Bio: Banjara Kotresha is an academic researcher from National Institute of Technology, Karnataka. The author has contributed to research in topics: Heat transfer & Porous medium. The author has an hindex of 4, co-authored 9 publications receiving 47 citations.

Numerical Simulations of Fluid Flow and Heat Transfer through Aluminum and Copper Metal Foam Heat Exchanger – A Comparative Study

Abstract: This article discusses about a numerical simulation of a metal foam heat exchanger system carried out by a commercial software. A metal foam layer is attached to the bottom of the heat exch...

Numerical Simulations of Flow-Assisted Mixed Convection in a Vertical Channel Filled with High Porosity Metal Foams

Abstract: In this work, two-dimensional numerical simulations of flow-assisted mixed convection in a vertical channel filled with high porosity metal foams have been carried out by using the commercial ANSYS...

Investigation of Mixed Convection Heat Transfer Through Metal Foams Partially Filled in a Vertical Channel by Using Computational Fluid Dynamics

Abstract: Two-dimensional computational fluid dynamics simulations of mixed convection heat transfer through aluminum metal foams partially filled in a vertical channel are carried out numerically. The objective of the present study is to quantify the effect of metal foam thickness on the fluid flow characteristics and the thermal performance in a partially filled vertical channel with metal foams for a fluid velocity range of 0.05–3 m/s. The numerical computations are performed for metal foam filled with 40%, 70%, and 100% by volume in the vertical channel for four different pores per inch (PPIs) of 10, 20, 30, and 45 with porosity values varying from 0.90 to 0.95. To envisage the characteristics of fluid flow and heat transfer, two different models, namely, Darcy Extended Forchheirmer (DEF) and Local thermal non-equilibrium, have been incorporated for the metal foam region. The numerical results are compared with experimental and analytical results available in the literature for the purpose of validation. The results of the parametric studies on vertical channel show that the Nusselt number increases with the increase of partial filling of metal foams. The thermal performance of the metal foams is reported in terms of Colburn j and performance factors.

Effect of thickness and thermal conductivity of metal foams filled in a vertical channel – a numerical study

Abstract: Purpose This paper aims to discuss about the two-dimensional numerical simulations of fluid flow and heat transfer through high thermal conductivity metal foams filled in a vertical channel using the commercial software ANSYS FLUENT. Design/methodology/approach The Darcy Extended Forchheirmer model is considered for the metal foam region to evaluate the flow characteristics and the local thermal non-equilibrium heat transfer model is considered for the heat transfer analysis; thus the resulting problem becomes conjugate heat transfer. Findings Results obtained based on the present simulations are validated with the experimental results available in literature and the agreement was found to be good. Parametric studies reveal that the Nusselt number increases in the presence of porous medium with increasing thickness but the effect because of the change in thermal conductivity was found to be insignificant. The results of heat transfer for the metal foams filled in the vertical channel are compared with the clear channel in terms of Colburn j factor and performance factor. Practical implications This paper serves as the current relevance in electronic cooling so as to open up more parametric and optimization studies to develop new class of materials for the enhancement of heat transfer. Originality/value The novelty of the present study is to quantify the effect of metal foam thermal conductivity and thickness on the performance of heat transfer and hydrodynamics of the vertical channel for an inlet velocity range of 0.03-3 m/s.

Thermal performance analysis of metallic foam-based heat sinks embedded with RT-54HC paraffin: an experimental investigation for electronic cooling

Abstract: Present experimental investigation focuses on the performance analysis of metallic foam and phase change material (PCM)-based heat sink at variable heat loads. High porosity (97%) copper and nickel foams are used with PCM (RT-54HC) to enhance the surface area for the heat transfer. Experimental results reveal that metallic foam-based heat sink embedded with PCM can reduce the base temperature of the heat sink efficiently. Copper foam is recognized to be more promising when compared to nickel foam in lowering base temperature for all heat loads (8 W, 16 W and 24 W). It was found that copper foam embedded with 0.8 volume fraction of PCM reduced the base temperature by 26% as compared to that of nickel foam without PCM at 24 W. Furthermore, when the PCM fraction is increased, final temperature of the heat sink gets lessened at the end of charging process while discharging process remains almost intact. So, in this study, copper foam with 0.8 volume fraction is determined to be an optimized configuration.

Experimental Study on the Thermal Performance of a Finned Metal Foam Heat Sink with Phase Change Material

Abstract: The present research conducts an experimental study on the thermal performance of the finned metal foam (FMF) heat sinks with phase change material. The dynamic temperature response of an FMF heat ...

A review on thermal application of metal foam

Abstract: Heat exchangers embedded with metal foam are drawing increasing attention in the thermal application field, due to the performance of low density, large ratio of surface area to volume as well as high thermal conductivity. In these applications, compact heat exchanger, solar thermal facilities and thermal energy storage are the three core components. This paper focuses on the lasted advances in thermal applications, presenting a review of theoretical and experimental progress over metal foam in thermal application. The empirical and theoretical models for pressure drop, heat transfer coefficient and performance evaluation criteria of compact heat exchangers with metal foam are reviewed and discussed, especially different optimized configurations. There is a trade-off between heat transfer enhancement and increase of pressure drop. Some exploratory work performed by present authors are also introduced. The manufacturing, heat transfer and flow characteristics of tube bundle wrapped with metal foam are taken into account for optimization of heat exchanger. It is confirmed that the conversion mechanism of heat transfer is carried out that heat conduction is the dominative term at high dimension permeability. The correlations of heat transfer rate and pressure drop for staggered and single row tube bundle wrapped with metal foam are concluded, respectively. The effects of different bonding methods are revealed for point-contact in metal foam and base tube. The powder-sintering method can provide a stable and minimum-thickness bonding layer. Various types of solar thermal facilities utilized metal foam to improve the energy conversion efficiency from solar radiant energy to thermal energy are also reviewed and discussed, including solar collector for intermediate-low temperature utilization and solar receiver for high temperature utilization. The Last but not least, existing and future metal foam thermal application stations are overviewed.