Thermal management of high power electronics for aerospace applications frequently utilizes liquid or air-cooled cold plates with embedded fin cores. These commonly used cold plates use fin assemblies with small flow passages and large area enhancements to achieve high levels of heat transfer performance. The design of this type of cold plate is well documented in the literature, with the most common methodology utilizing “f” and “j” test data as a function of Reynolds Number. This paper presents a technique termed “network modeling” that simplifies the modeling of cold plate features within a CFD model. This technique greatly reduces model size and CPU time needed for solutions. In addition, it is inherently accurate because it allows test data to be incorporated into the model. Simplification of the performance of coldplate features within a system level CFD thermal model is a great advantage, as modeling these small coldplate features is a tedious task and often unnecessary. The methodology presented uses a convective resistance network with mass flow links and convective links to describe the overall thermal behavior of the coldplate. This simplified network model can be used within a detailed thermal model of the electronics assembly to provide an accurate simplification of the coldplate performance for temperature and heat flow prediction. Since the network technique simplifies the flow boundary conditions, the detailed thermal model can contain as much internal details of an electronics assembly as desired, while still keeping the overall model size manageable and CPU times minimal. This network-based method of modeling coldplate should be very accurate because it is based upon established test data of “f” and “j” as the basis of the model. This network method has significant advantages over the other methods of heat exchanger simplification such as coarse mesh, effective thermal conductivity, source-sink, etc. This paper describes the creation of such a network, integration in an ICEPAK thermal model, discussion of the advantages, and results.
Review and Analysis of the Reasons Delaying the Entry into Service of Power-by-Wire Actuators for High-Power Safety-Critical Applications
