A blood warmer is often used in certain clinical transfusion procedures. While safely storing and preserving blood requires refrigeration, cold blood when used in rapid transfusion procedures could cause clinically dangerous hypothermia in a patient. A new compact and miniature heat exchanger has been proposed that is used “inline” with the transfusion delivery system. It consists of a multitube bundle of 5-mm diameter tubes arranged in an equilateral-triangular array with tube centers 7.5 mm apart. Blood flows inside the tubes and is warmed by a heated airstream that is in external cross flow such that the tube surface is maintained at 40°C. The inlet air flow to the tube array is at 70°C with a free stream velocity of 2 m/s, and there are five lateral or transverse rows in the bundle. Determine the average heat transfer coefficient and pressure drop in the airstream. Also, what is the change in both of these quantities if the tube center-to-center pitch is reduced to 6.0 mm?