Numerical investigation of conjugate heat transfer from a flush heat source on a conductive board in laminar channel flow

Abstract

A numerical investigation was conducted on the heat transfer from a uniformly powered strip source of heat that is located on the surface of a two-dimensional conducting substrate. The upper and lower surfaces of the substrate are cooled by forced laminar flow that is two-dimensional, steady, and with constant properties. The problem is a paradigm for the investigation of the competing effects of substrate conduction and fluid convection in the cooling of electronic components, i.e. chips or chip carriers, on boards or substrates that are cooled by air flowing parallel to the surface. The objectives of the study were to investigate the conjugate heat transfer mechanisms in great detail and in a methodical way, such as to use the results as a baseline for succeedingly more complex situations of air-cooling of component on board situations. Results are presented for substrate conductivity to fluid conductivity ratio, ks/kf from 0.1 to 100, channel Reynolds number from order 100 to order 1000, corresponding to air velocities of order 1 m/s, and for both developing and fully-developed laminar parallel planes channel flow.