It has been suggested that heat transfer from a surface can be augmented by wetting it with water. As a spe- cific example, consider a horizontal tube that is exposed to a transverse stream of dry air. You may assume that the tube, which is maintained at a temper- ature Ts > Too, is completely wetted on the outside with a thin film of water. Derive an equation to determine the extent of heat transfer enhancement due to wetting. Evaluate the enhancement for V = 10 m/s, D = 10 mm, Ts = 320 K, and Too = 300 K.