VELOCITY AND CONCENTRATION DISTRIBUTION IN A STEFAN DIFFUSION TUBE

Publisher Website
Google Scholar
Abstract
Numerical solutions for the diffusion- and gravity-driven flow in a cylindrical Stefan tube were obtained from the coupled diffusion and Navier-Stokes equations for Peclet numbers, NPe = 0.3, 1 and 5. Distributions of binary component concentrations and velocities were calculated. The mass average velocity is parabolic in nature, except at high NPe . The solvent is not stagnant but recirculates, even in the absence of gravity. Radial concentration gradients develop which act convectively destabilizing. Consequences for the deduction of diffusion coefficients from Stefan tube experiments are discussed.

This publication has 5 references indexed in Scilit: