Natural Convection Mass Transfer Adjacent to Vertical and Downward-Facing Inclined Surfaces

Experimental measurements for natural convection mass transfer adjacent to vertical and downward-facing inclined surfaces were performed using an electrochemical technique. The measurements yielded the time average and instantaneous mass transfer rates for the laminar, transition, and turbulent flow regimes along the test surface. The laminar mass transfer measurements were found to agree with both the analytical and experimental results for both the vertical and downward-facing inclined surfaces. The Rayleigh number marking the onset of the transition from laminar flow conditions depended heavily upon the angle of inclination of the test surface. In the turbulent regime the time average local mass transfer coefficient was correlated by the Rayleigh number to 1/3 power.