CBE 320November 4, 2013Transport PhenomenaProblem Session XPart A: Shell Energy Balances1.Work problem 10B.9(a) in BSL.2.Energy Transport in a CPU Heat SinkTo keep some computer CPUs from overheating, heat sinks are placed on top of the CPU (along witha fan). The heat sink is essentially a collection of cooling fins; this is illustrated in the left figurebelow, where the fins are cylindrical.Consider one of the fins in the heat sink, depicted in the right figure. We treat the fin as a cylinder (ra-diusb, lengthL) attached to a wall. The wall temperature isunknown(findingTwallis the goal of thisproblem), but the rate of heat transfer from the wall to the finQ([=]energy/time) is known from thepower used by the CPU. Energy is conducted down the fin (thermal conductivity
