Air at 2 atm and 500 K with a velocity of u∞ = 20 m/s flows across a PVDF compact heat exchanger matrix studied by Cheng and Van Der Geld44 having the configuration shown in Figure 13.5. By assuming that the PVDF heat exchange surface is similar to the surface 9.68-0.870 and using the length of the matrix as 48 plates with 4 mm per plate, calculate the heat transfer coefficient and the frictional pressure drop.