An electronic device that internally generates 600 mW of heat has a maximum permissible operating temperature of

Question:

An electronic device that internally generates 600 mW of heat has a maximum permissible operating temperature of 70?C. It is to be cooled in 25?C air by attaching aluminum fins with a total surface area of 12 cm2. The convective heat transfer coefficient between the fins and the air is 20 W/(m2 K). Estimate the operating temperature when the fins are attached in such a way that:(a) There exists a contact resistance between the surface of the device and the fin array of approximately 50 K/W, and(b) There is no contact resistance but the construction of the device is more expensive. Comment on the design options.GIVENAn electronic device with aluminum fin arrayDevice generates heat at a rate ( qG ) = 600 mW = 0.6 WSurface area (A) = 12 cm2Max temperature of device = 70?CAir temperature (T??) = 25?CConvective heat transfer coefficient ( hc ) = 20 W/(m2 K)ASSUMPTIONSOne dimensional heat transferSteady state has been reachedThe temperature of the device is uniformThe temperature of the aluminum fins is uniform (the thermal resistance of the aluminum is negligible)The heat loss from the edges and back of the device isnegligible