Simultaneous heat and mass transfer through laminar boundary layers in combined forced and free convection

Heat and mass transfer rates from a vertical plate are reported for combined free and forced convection. Heat transfer coefficients were obtained from temperature gradients at the wall and mass transfer rates from thickness decrease measurements of naphthalene coatings. The free convection data cover a Grashof number range from 100 to 2 × 10⁸ and the combined flow parameters Gr/Re² and Gr'/Re² vary from 0.2 to 100 and 2 × 10^?8 to 3.25, respectively. Predictions from boundary layer solutions are in good agreement with the data. Absorption of ultraviolet light by naphthalene vapor was used to measure free convection concentration profiles. Results prove the versatility of this method.