Optimization of PCM-Based Heat Sink Under Cyclic Heat Load


Sandip K. Sahaa and Pradip Duttab

Department of Mechanical Engineering, Indian Institute of Science, Bangalore 560 012, Karnataka, India.

asandip@mecheng.iisc.ernet.in
bpradip@mecheng.iisc.ernet.in

ABSTRACT

The role of melt convection on the performance of heat sinks with Phase Change Material (PCM) under cyclic operation is presented in this paper. The heat sink consists of aluminum plate fins embedded in PCM and heat flux is supplied from the bottom. The design of such a heat sink requires optimization with respect to its geometrical parameters. The objective of the optimization is to minimize the temperature rise in the heating period for the prescribed heat flux and complete solidification of PCM at the end of the cooling period for a given cycle. The parameters considered for optimization are fin number, fin thickness and fin height. The length and base plate thickness of heat sink are kept constant in the present analysis. An enthalpy based CFD model is developed, which is capable of simulating phase change and associated melt convection. The CFD model is coupled with Genetic Algorithm (GA) for carrying out the optimization. Two cases are considered, one without melt convection (conduction regime) and the other with convection. It is found that the geometrical optimizations of heat sinks are different for the two cases, indicating the importance of melt convection in the design of heat sinks with PCM.

Keywords: Electronics cooling, Phase Change Materials, Cyclic operation, Optimization, Genetic algorithm, Melt convection.



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