Numerical study on some improvements in the passive cooling system of a radio base station base on multiscale thermal modeling methodology-part ii-results of multiscale numerical simulation and subsequent improvements of cooling techniques

In the companion article (Part I), simplified compact model of components in a system level model was established based on heat transfer path and thermal resistance network analysis. In this article, component level simulation and lead level simulation was conducted by assiging the boundary conditions from the data of the higher level simulation, and effects of different boundary conditions on numerical accuracy and stability are studied. Comparison shows that multiscale thermal modeling methodology can save 87% of the total computation time compared with full simulation with a fine grid system, and can greatly improve the resolution of the calculation result. Mainly based on the multiscale simulation five improvements for the reduction of the maximum PCB temperature are proposed. This article also provides an example that by a careful numerical thermal design, a passive cooling mode can sometimes meet the cooling requirement of a PCB with high power input in some extent.