Mass transfer from inclined cylinders at moderate Rayleigh number including the effects of end face boundary conditions

Natural convection from inclined cylinders is studied using an electrochemical mass transfer technique. The effect of end face boundary conditions (active vs inactive) has been studied for a range of Rayleigh numbers 4 × 10⁹ < Ra_L* < 1 × 10¹², angles of inclination 0°, 30°, 60° and 90°, cylinder aspect ratios (length-to-diameter) of 0.63, 1.48 and 2.34 and a nominal Schmidt number of 2280. The data indicate that at these aspect ratios, the boundary condition on the bottom end face significantly affects the mass transfer on the curved part of the cylinder, due to depleted solution from the bottom rising along the cylinder. Inactive base data can be correlated by a single length scale that includes the effect of aspect ratio as well as inclination angle. Active base data do not correlate with this length scale, but match well with the sum of correlations for the mass transfer from downward-facing discs and the inactive base data in the current study.