Thermal Management of an Aerospace Power Electronic DC/DC Converter: Design and Development of Liquid Cold Plate

Abstract

High power density power electronics demand has been increasing in these years and the thermal management systems for power electronics is becoming a challenge. It is critical to have enough cooling power within a limited space. By considering the packaging of the power electronics, the cooling solution needs to be efficient, reliable, compact and cost-effective. This thesis is to investigate the performance of different fin geometries of a liquid cold plate in a 20Kw DC-DC converter that will be applied in aerospace applications. It is also used to design a new optimized cold plate to replace the previous prototype of the converter for improvement. Four different fin shapes and 5 different strut thicknesses of the Body-Center-Cubic (BCC) lattice structure cold plate models are studied and comparatively analyzed. Some cooling system performance metrics like pressure drop, heat transfer coefficient and thermal performance index are used to evaluate the models. The material selection and fabrication methods for the cold plate are also explored. The models are simulated with CFD software with mesh independence study. The original model is being manufactured and tested to validate the simulation results. The new design model is simulated and in the manufacturing phase. Based on the simulation results, the oblong-shaped pin fin cold plate has the highest thermal performance index value, BCC lattice structure cold plate has a better heat transfer rate than pin fin geometries but it trades off with hydraulic performance. And the new prototype cold plate can provide better cooling power with packaging and pumping power requirements.