Horizontal Simulated Printed-Circuit Board Assembly in Fully-Developed Laminar-Flow Convection

摘要

Steady-state convective heat-transfer and pressure-drop characteristics for laminar air-flows over a horizontally-orientated simulated printed-circuit board (PCB) assembly have been measured experimentally and predicted numerically. The considered assembly consisted of a plate with uniformly- spaced identical electrically-heated rectangular uniform ribs mounted orthogonal to the mean air-flow. Mathematical correlations were deter- mined between the cavity-height to ribs' protrusion and width-to-protrusion ratios, namely (H/B) and (L/B), respectively, and the Reynolds number (Rec) of the air-flow with the steady-state Nusselt number (Nut) and friction factor (fc), both of these latter parameters being highly dependent on H/B. When H/B>=8, natural convection provided a significant portion of the total rate of heat transfer, and mixed (i.e. forced plus natural) convec- tion ensued.