Numerical analysis of convective drying of a moist object with combined internal and external heat and mass transfer

A numerical approach is developed for computing convective drying of a moist object. The conservation equations of mass, momentum, energy and moisture in the internal and external regions of an object are solved with the coupled heat and mass transfer conditions on the object surface, including the effect of evaporation. A numerical approach is applied to predict the internal and external temperature and moisture distributions during the convective drying with variations in the initial moisture content and the water activity. The numerical results show that the water activity is an important parameter for determining the drying rate pattern and the analogy between the heat and mass transfer on the object surface.