Heat pipe models in thermal design software including realistic representation of thermal resistance and heat transport limit

This paper reports on the predictive capabilities of a new commercial software called aCool with a more sophisticated representation of heat pipes that accounts for both the thermal resistance and the heat transport limitations in CFD models of thermal solutions such as heat sinks. Rather than rely solely on the theoretical heat transport capabilities of heat pipes, the properties of the heat pipes in the software are based on experimentally measured characteristics of real production copper-water heat pipes including real world defects in the wick, effects of gravity, changes in wick types along the length of the heat pipe, and changes in heat transport limits with temperature. The aCool representation of heat pipes is validated against our experimental measurements for three test case studies. The test cases include heat transport through heat pipes in a stand-alone configuration, heat spreading in the base of a heat sink for insulated-gate bipolar transistors (IGBT) cooling, and base spreading in a heat sink with an uneven air flow distribution through the fins.