Free Convection Cooling of Electronic Systems

Design criteria for free convection cooling c,f electronic systems are considered, The primary emphasis is on electronic equipment in which vertically oriented circuit cards are aligned to form vertical channels. Results of an experimental study utilizing a simulated electronic cabinet are discussed and compared with theoretical solutions obtained by numerical integration of the partial differential equations governing the heat transfer. Good agreement is shown between predicted and measured card temperatures for several different card spacings. Parametric effects on the maximum card temperature are given for card spacing, heat dissipation, and channel height. Nomograms are developed for rapid estimation of card temperatures and for choosing optimum card spacings. The effects of channel flow restrictions, staggered cards, and baffles are also discussed.