Modeling simultaneous heat and mass transfer using the control-volume method

A control-volume formulatian for the solution of a set of two-way coupled heat and diffusive moisture transfer equations is presented in three dimensions. The three-dimensional model in Cartesian coordinates was extended to other geometries using an equivalent surface area-to-volume ratio index. The solution procedure developed uses a fully implicit time-stepping scheme for the solution of the coupled set of equatians to study the drying behavior of barley and starch food. Simulated results of the one-way and the two-way coupled equations were compared with the finite-element analysis (two-way coupled and three-way coupled equation set) and experimental results from the literature. Among the products tested, the maximum deviations between experimental and simulation results were 5.0°C in temperature for barley drying, and 0.2% moisture for starch drying. The overall predictions agreed well with the available experimental data and show good potential for application in grain and food drying.