A Mathematical Model on Heat Mass Transfer Including Relaxation Time for Different Geometries During Drying of Foods

Abstract

In this paper, a single phase lag model on heat mass transfer in application of food drying has been developed. The present model is a generalization of the diffusion model. The whole analysis is presented in nondimensional form. The effects of shape parameter, relaxation time parameters, Luikov number, Kirpichev number, Biot number, Kossovich number, and Predvoditelev number on heat and mass transfer are discussed in detail. For experimental validation, we have taken examples of banana, mango, and cassava. Our simulations show that the present model is more suitable than diffusion model. The present model is in good agreement with experimental data. The moisture potential of slab food is higher than cylindrical food and moisture potential of cylindrical food is higher than spherical food for boundary condition of first, second, and third kinds. It has been observed that the moisture potential is highest in boundary condition of second kind and lowest in boundary condition of the third kind while in between in boundary condition of the first kind. We conclude that for complete drying, the spherical shape foods takes lesser time than cylindrical shape and cylindrical shape takes lesser time than slab shape.