Simplified numerical modelling of infrared radiation effects in tomato dry peeling

Abstract

Abstract In view of the increasing interest in developing sustainable systems for tomato peeling, the unsteady thermal field in a rotating tomato exposed to an array of infrared emitters was studied. First, a predictive 3D numerical model was developed to simulate heat transfer in a rotating tomato undergoing infrared heating. Since simulations required great computational efforts, it was considered appropriate to introduce a simplified model. To this purpose, the net radiative heat flux on the tomato surface was approximated by a suitable periodic function: the related angular velocity accounted for tomato rotation, while its amplitude was linked up with view factors between the tomato and the heating source. On such basis, a 1D axisymmetric model involving radiative heating from the source regarded as a periodic II-type boundary condition was set up. It was found that temperatures predicted by the simplified model agreed well with the 3D model output. Finally, a parametric analysis was performed to investigate the effect of the position and angular velocity of the tomato samples on the rate and uniformity of IR heating. Results were pursued both by the 3D and 1D model, in the latter case obtaining faster yet accurate responses.