Design micro-channel heat sinks using mathematical optimization with variable axial length

Abstract

Paper presented at the 7th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Turkey, 19-21 July, 2010.

This paper documents the geometrical optimization of a micro­-channel heat sink with a relaxed axial length. The objective is to optimize (minimize) the wall peak temperature of the heat sink subject to various constraints such as manufacturing restraints, fixed pressure drop and total fixed volume. A gradient based optimization algorithm is used as it adequately handles the numerical objective function obtained from computational fluid dynamics simulation. Optimal geometric parameters defining the micro-channel were obtained for a pressure drop ranging from 10 kPa to 60 kPa corresponding to dimensionless pressure drop of 6.5x107 to 4x108. The effect of pressure drop on the aspect ratio, solid volume fraction, channel hydraulic diameter and the minimized peak temperature are reported. Results also show that as the pressure drop increases the maximum global thermal conductance also increases. These results are in agreement with previous work found in literature.