Soluções híbridas dos problemas de transferência simultânea de calor e massa com fronteira móvel VIA GITT

Abstract

This work presents an analytical-numerical hybrid solution for the simultaneous transfer of heat and mass in horizontal and vertical absorbers with a fully developed constant velocity profile, using rectangular and cylindrical coordinates, respectively. These problems were solved using the Generalized Integral Transform Technique using a change of variable to determine the film thickness. This technique allowed analytical manipulations of the systems of partial differential equations and used filters in their boundary conditions, to make the problem homogeneous, in order to produce systems of ordinary differential equations for the transformed potentials. An integral balance was applied to allow coherent results of the potentials and their flows in the boundary conditions. The mathematical model used the heat transfer equation subject to the Robin boundary condition (third type) and the mass transfer equation subject to the Neumann boundary condition (second type), to calculate the heat and mass transfer rates varying the Biot number and the coupling factor. To validate the proposed model, several situations were simulated: Bi=0.001 (adiabatic wall), Bi=0.1,1,2,5 and 10 (intermediate cases) and Bi=1000 (isothermal wall). The temperature and concentration profiles were also determined and compared with results available in the literature, obtaining good results. A parametric study was carried out with a simulation tool based on the model presented. This study highlights that varying the Biot number shows that the influence in the thermal field is greater than in the concentration field, while varying the coupling factor shows that the influence in the concentration field is greater than in the temperature field.