Transporte de calor e massa em sólidos porosos heterogêneos com geometria arbitrária via método da análise concentrada: modelagem fenomenológica difusiva-convectiva e simulação.

Abstract

This work aims to theoretically study the phenomena of heat and mass transfer in heterogeneous solids with arbitrary shape. Based on the method of lumped analysis, phenomenological mathematical models were developed to predict the convective drying process considering the simultaneous phenomena of diffusion inside and convective on the surface of the heterogeneous solid. For the analytical solution of the system of governing equations, the classical method of solving ordinary differential equations was used. Application has been made for drying of porous, cylindrical, hollow and corrugated solids. Different cases were simulated, varying the shape of the body, from which the kinetics of drying (moisture loss) and heating (temperature increase) were obtained in each material that composes the heterogeneous solid. Moisture content results were compared with data reported in the literature and a good concordance was obtained. It was observed that the moisture removal process occurs at a lower speed than the heating of the heterogeneous solid, and that the shape of the solid, particularly its area/volume ratio strongly affects the phenomena of heat and mass transport in each material that makes up the heterogeneous solid. The proposed modeling has great potential to describe successful drying, humidification, heating and cooling processes.