Effect of Thermal Conductivity on Cooling of Square Heat Source Array under Natural Convection in a Vertical Channel

Abstract

This article presents experimental and numerical investigation on natural convection air-cooling of discrete square heat source array in a vertical channel. Conjugate heat transfer for three-dimensional laminar developing flows over an array of square heat sources representing integrated circuit components for electronic cooling has been studied. Experiments are conducted using three-substrate board materials viz. FR4, Bakelite, and copper clad board having thermal conductivities of 0.3, 1.4, and 8.8 W/m K to study the effects of substrate thermal conductivity on fluid flow and heat transfer. A finite element-based software is used to solve the coupling between heat transfer in solids and fluid region. Incompressible flow over discrete square heat sources is modeled using Navier–Stokes equations under Boussinesq approximation. Air-cooling of circuit boards populated with heat sources is modeled and simulated to present heat transport in combination with the fluid flow resulting from the natural air circulation at constant heat fluxes of 1,000, 2,000, and 3,000 W/m². Multilayer copper clad board of thermal conductivity of 40.5 W/m K have been studied numerically. The results show that single sided copper clad board is the preferred candidate. Experiments indicate a deviation of under 5% with simulations.

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Notes on contributors

Shankar Durgam

Shankar Durgam is an Associate Professor in the Department of Mechanical Engineering, Jawaharlal Darda Institute of Engineering and Technology Yavatmal, India. He received his Ph.D. degree in Mechanical Engineering from Indian Institute of Technology Madras, India, in 2017. His major research interests are broadly in heat transfer and fluid flow including conjugate heat transfer, laminar and turbulent flows. He is interested in both experimental and numerical research. He is currently working on natural, forced, and mixed convection with emphasis on the areas of electronic cooling and high heat flux thermal design. He has been a Summer Faculty Research Fellow at Indian Institute of Technology Delhi.

Shakkottai P. Venkateshan

Shakkottai P. Venkateshan is a professor emeritus in the Department of Mechanical Engineering, Indian Institute of Information Technology Design and Manufacturing Kancheepuram, Chennai, India. He received his Ph.D. degree from IISc Bangalore, India, in 1977. After spending three years at Yale University, he joined Indian Institute of Technology Madras in 1982. His research interest in a broad sense includes interaction of natural convection with radiation, numerical and experimental heat transfer, heat transfer in space application, radiation heat transfer in participating media, and instrumentation. He has been a consultant to ISRO, DRDO, and BHEL in India and NASA in the United States. He has three patents to his credit in the area of instrumentation. He has published more than 100 research papers in national and international journals and conferences and has authored three textbooks. He has produced several video lecture series, including one on mechanical measurement, that are broadcast on the Eklavya Technology Channel, dedicated to technical education.

Thirumalachari Sundararajan

Thirumalachari Sundararajan obtained his Bachelor’s degree from Indian Institute of Technology (IIT) Madras in Mechanical Engineering in 1978 and later MS and Ph.D. degrees from the University of Pennsylvania, Philadelphia, USA in 1980 and 1983, respectively. After working as a postdoctoral fellow at the University of Pennsylvania during 1983–1984, he joined as Assistant Professor at IIT Kanpur, India in 1985. Presently, he is a full Professor at IIT Madras in the Department of Mechanical Engineering. He has published about 190 journal papers and presented more than 150 papers in various conferences. He has also published a textbook on computational fluid dynamics. He has been nominated as a Fellow of Indian Academy of Engineering (FNAE) in 2003 and received the Astronautical Society of India Award for Rocket Technology in 2006. His areas of research include combustion & propulsion modeling, nano-fluid heat transfer, electronic cooling, fuel cells, two-phase flow, nuclear thermal hydraulics, and solar thermal power generation. He has been awarded the Institute Chair Professorship by IIT Madras from June 2017.