# Heat Transfer Fin Problem

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1. Nov 6, 2015

### acox20

Hey, long time reader, new user. I have a probably simple fin question. If you all don't mind.
I honestly just need to nail down the equations. Don't quite need a solution.
A fan blows air over the top surface of a hot electronic component (size of 10 mm x 10 mm) with an average convective heat transer of 50 W.m^2k. If a longitundinal finned heat sink is added to this top surface, estimate the ratio of heat transfer rates from the chip surface to air with and without heatsink. The base of the heat sink is 1 mm think and has the same size as the chip. The heat sink has 12 rectangular fins, each .5 mm thick and 10 mm wide. The total hight of the heat sink including the base and the fines is 16mm. Both air and chip top surface tempertures are fixed and known. I am supposed to assume that the heat sink is made of an alluminum alloy with a termal conductivity of 160 W/mK and that the fins are infinitely long. Does it justify using the finned heat sink in this case? Thank you for you efforts.

2. Nov 7, 2015