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-ow at a 1' velocity of 10 ms . Cylindrical fins with a diameter of 15 mm and square fins with the same cross-sectional area are being considered. In addition, two different cross-ow congurations for the square fins are to be evaluated: cross-ow normal to a face and cross-ow normal to a diagonal. For tins of equal length, which fin configuration will result in the largest heat transfer rate? You may use the properties of air at 80 'C' H = 2.09x10-5 miss1; Pr = 0.7) and assume the fins to be infinitely long