Thermal modelling of a heat block and heat sink connected by heat pipes using finite element methods
ENGLISH ABSTRACT: This article considers the heat transfer between a simple heat block and a heat sink, using heat pipes as the energy transport medium. Both the heat block and heat sink are made from carbon steel. The heat pipes have copper containers and uses water as the working fluid, with a phosphor bronze mesh wick. The source, sink and heat pipe combination were modelled using finite elements. The program used was Nastran 2.0 for Windows, although the finite element application would be universal. The heat pipe was assigned constant properties, namely density, specific heat capacity and also conductivity. The purpose of the research was to investigate the merits of using constant properties for heat pipes in a finite element simulation. Using constant properties is a significant simplification of the complex internal thermo-fluid processes of a heat pipe, and will result in much faster calculation times. The results indicated though that this type of simplification may lead to inaccuracies. It would be beneficial if a heat pipe property can be developed and assigned to a three dimensional finite element. Another (and maybe more realistic) option would be to rather do modelling of heat pipes with a finite element based program that is able to incorporate non-linear boundary conditions, with which the heat pipe’s boiling and condensation processes can be modelled.