Geometric optimisation of forced convection in a vascularised material

Abstract

Paper presented at the 8th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Mauritius, 11-13 July, 2011.This paper presents a three-dimensional geometric optimisation of cooling channels in forced convection of vascularised material with the localised self-cooling property subject to heat flux. Square configuration was studied for family of porosities. The configuration geometry was optimised in such a way that the peak temperature was minimised at every point in the solid body. The optimisation was subject to the constraint of fixed global volume of solid material, but the elemental volume was allowed to morph. The solid material was subject to heat flux on one side and the cooling fluid was forced through the channels in opposite direction of the heated side of the solid body by the specified pressure difference across the transverse channels in the body. The structure had three degrees of freedom as design variables: elemental volume, channel hydraulic diameter and channel-to-channel spacing. A gradient-based optimisation algorithm was used to determine the optimal geometry that gave the lowest thermal resistance. This optimiser adequately handled the numerical objective function obtained from CFD simulations. The numerical results obtained show that as pressure difference increases, the minimised peak temperature decreases. The results also show the behaviour of the applied pressure difference on the optimised geometry. The use of optimiser made the numerical results to be more robust with respect to the optima internal configurations of the flow systems and dimensionless pressure difference.