On the Sherwood number correction due to Stefan flow
Maulana Gilar Nugraha, Ronnie Andersson, Bengt Andersson
Abstract
This study contributes with insight and new models for mass transfer to spheres for three different conditions i.e. mass transfer without Stefan flow, mass transfer with even Stefan flow and mass transfer with uneven flux driven Stefan flow. High resolved computational fluid dynamic simulations of mass transfer without Stefan flow resulted in a new correlation that improves the prediction compared to the model suggested by Ranz-Marshall particularly for higher Sc numbers. A new model for mass transfer which accounts for the convective transport within the ‘film’ surrounding the particle, and an increase in the film thickness due to the Stefan flow was successfully derived. It is concluded that the new model provides improved accuracy compared to the Spalding and Abrahamzon models and that the relative error for the Sherwood number can be reduced by about half.