A circuit board with a length of 120 mm and a width of 120 mm is cooled by air at atmospheric pressure anda temperature of T∾290 K flowing with a velocity of V∾ 2 m/s past the top surface. From wind tunnel tests under the same flow conditions, the average frictional drag coefficient on the upper surface is Cₗ = 0.0266. When in service, the average surface temperature of the circuit board must not exceed the ambient air temperature by more than 20°C.

Calculate the average convection heat transfer coefficient for the top surface. You must use an appropriate momentum and heat transfer analogy to reveice credit.