Paper presented to the 10th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Florida, 14-16 July 2014.
With the increase in power consumption within a limited volume of present day power electronics, heat sink design has become a central aspect of thermal management of these devices. In this study, a plane fin heat sink with surface augmentation was optimized to meet and exceed the operating requirements of DARPA’s Microtechnologies for Air Cooled Exchangers (MACE) program. To accomplish the computational efficiency required of a multi-parameter optimization problem, conjugate heat transfer and fully developed flow were modeled using Volume Averaging Theory (VAT). By modeling a highly detailed heterogeneous structure as a homogeneous porous medium, VAT based numerical simulation overcomes the meshing difficulties and computational cost associated with traditional CFD methods. The configuration considered was elliptic scales located on the fin surfaces where the scale height, transverse pitch, and longitudinal pitch were variable. These parameters along with fin base thickness, tip thickness, and fin pitch were varied simultaneously while the heat sink length (101.6mm), width (101.6mm), and height (25.4mm) were held constant. Design of Experiments (DOE) software was used to conduct a Response Surface Methodology (RSM) design to minimize the thermal resistance with constant pumping power as the flow condition. The optimized heat sink presented has a thermal resistance of 0.0246°C/W when cooled by air with a pumping power of 33W.