3rd Report (An Experimental Investigation of Free Convection Cooling of Electronic Equipment)

An experimental study of free convection cooling of electronic components on PWB, which was placed horizontally in the cabinets, was carried out using the following two types of model cabinet. (1) The cabinets (200×150mm in cross section, 80mm high), which were made of acrylic resins plates (4mm thick), had the ventilating small holes in the top panel and the bottom panel of them. (2) The two-dimensional models of the cabinet (160×380 m in cross section and 80 m high) had many slits in the top panel of them. Numerical values of velocity of the ventilation, which were estimated by the heat balance analysis using the measured temperature, agreed with the values directly measured by LDV. It was demonstrated that the flow rate of ventilation could be estimated using the obtained relation between the ventilating air velocity and the mean temperature excess on the inner wall surface of the cabinets.