Air flows over two identical flat plates (A and B) as shown in the figure below. The plates are made of naphthalene which sublimes into the flowing air. Plate A is oriented with its long dimension, L, oriented perpendicular to the flow and its short dimension, W, is oriented with the flow. Plate B is oriented with its long dimension oriented with the flow. In both cases, L = 2W. Assume that the flow remains laminar in both cases. The free stream velocity (u), the bulk concentration of naphthalene in air (C), and the solubility of naphthalene in air, (Cs), are the same for both cases. Estimate the ratio of the total rate of mass transfer from plate A to the total rate of mass transfer from plate B.

UCO Coo L = 2W W Uoo Coo - L = 2W 1 V CS Cs Uo US Coo Coo plate A plate B