Numerical Prediction and Analysis of Surface Transfer Coefficients on Moist Object During Heat and Mass Transfer Application

Abstract

Convective surface transfer coefficients data for a moist object are not easily available from the literature and this coefficient is usually assumed to be constant in most studies. A three-dimensional (3D) numerical model is developed for prediction of heat and mass transfer coefficients on the surface of the rectangular moist object. A computational fluid dynamics tool is used for flow analysis at three different higher velocities. The spatial distribution of heat and mass transfer coefficients is estimated at the surfaces of the object. The effect of constant and variable surface transfer coefficient is analyzed through transient 3D simultaneous heat and mass transfer solutions of convective drying. The numerical results are compared with experimental results. Good agreement was found with the experimental results when the numerical solution is considered with variable heat transfer coefficient. The numerical solutions with constant heat transfer coefficient gives overestimated results. A new set of Nusselt number and Sherwood number correlations is developed from a numerical model, and these correlations are expected to be useful for drying industries.