FORCED CONVECTIVE AIR-COOLING OF SIMULATED PRINTED-CIRCUIT BOARDS

The considered assembly consisted of a simulated printed-circuit board (PCB), in this instance a horizontal, thermally insulting base with uniformly spaced rectangular copper bars-hereafter referred to as ribs, used to mimic the behaviour of electronic components-protruding upwards from the base. The assembly was mounted in a thermally well insulated, rectangular-sectioned duct, so that air could be sucked solely over the upper surface of the simulated PCB, the horizontal ribs were arranged to be orthogonal to the horizontal mean air-flow. Steady-state heat-transfer performance data, showing the influence of the geometry of the system, were measured A non-dimensional correlation, which can be used by designers to predict the steady-state rate of heat transfer from such a PCB assembly to the air flow, is Nu(c)BAR = 1.4 x 10(-2) Re(c)9.88 for 8.5 x 10(2) < Re(C) less-than-or-equal-to 3.5 x 10(4).