Scale Effects on Thermal-Fluid Performance of Optimized Hierarchical Structures

The development of an optimized cooling structure for high heat flux applications is described. A gradient-based method coupled with commercial multiphysics finite element software is used in the optimization process. The results are applied to the design of a combination manifold jet/channel cold plate. Three sizes of the structure ranging from mini to microscale are investigated in a subsequent numerical study, and the effect of size reduction on thermal-fluid performance is explained. It is found that smaller scaling of the cooling structure leads to reduced unit thermal resistance due to a fundamental shift in the behavior that exploits the jet-based characteristics of the design. A relevant application of the microscale technology is discussed.