Numerical modeling of evaporator surface temperature of a micro loop heat pipe at steady-state condition

Abstract

Numerical investigations have been performed to simulate a novel micro loop heat pipe (MLHP) under steady-state conditions. For most electronics, the maximum working temperature is an important design factor; therefore an accurate prediction of this temperature is crucial. The model predicts the steady-state temperature distribution at the surface of the heat source as a function of applied heat loads. This code builds upon a previous code developed by the authors (Ghajar et al 2005 J. Micromech. Microeng. 15 313–21), and utilizes a hybridizing of an alternating direction implicit (ADI) computational fluid dynamics (CFD) code and relevant thermodynamic equations. Using this simulation tool, the minimum required compensation chamber cavity has been calculated and checked for various operating temperature ranges. Additionally, the design of the MLHP has been improved by evaluating the effects of the geometric feature variations. Considering the fabrication constraints, some of the optimized geometry dimensions were found to be a groove wall thickness of 2 µm, a groove width of 7 µm, a wicking structure length of 500 µm and a vapor line width of 2 mm.