Unsteady heat-transfer analysis of spherical fruit to air flow

The present study deals with an analysis of unsteady heat-transfer during forced-air cooling of figs as spherical fruits. The heat-transfer mechanism in the cooling of fruits is quite complex. Conduction, convection, radiation, and internal heat generation take place. Moisture loss is coupled with heat transfer. The governing equations have been derived and simplified using well justified assumptions. An analytical scheme is presented for solving these equations for three cases, namely, h = hc, h = hc + hr, and h = hc + hr + hc. The predicted temperature distributions and heat-transfer rates for four air velocities are compared with the measured data. Predictions for the first and second cases are in good agreement and those for the third and most realistic case are in even better agreement with experimental observations.