1. To enhance heat removal from an electronic device, pin fins are to be installed on the surface of the

device. The fins will be subjected to 20°C atmospheric air in cross-flow at a velocity of 10 m/s. Cylindrical

fins with a diameter of 15 mm and square fins with the same cross-sectional area are being considered. In

addition, two different crossflow configurations for the square fins are to be evaluated: crossflow normal

to a face and crossflow normal to a diagonal. For fins of equal length, which fin configuration will result

in the largest heat transfer rate? You may use the properties of air at 80°C (v=2.09×10³ m²/s; Pr=0.7)

and assume the fins to be infinitely long.