Abstract
In the present work a numerical simulation of the natural convection process in a chemically reacting packed bed has been carried out. The simulation has been based on a Galerkin method of finite element formulation. An investigation of the transient as well as steady state results is presented. The heat source term is represented by an Arrtnhius-type source term, which typically represents several zero-order chemical reactions in practice. The ensuing transient process of natural convection in the cavity is investigated, and the effect of the temperature of the not boundary on the heat removal capacity is also presented. The critical boundary temperature that will result in the thermal runaway inside the cavity was investigated, and the effect of the boundary temperature on the thermal explosion in the cavity was also analyzed. It was found that the flow field was symmetrical about the vertical centertine and the temperatures continued increasing away from the horizontal walls of the cavity, thus giving hot spots in regions removed from the horizontal boundaries of the cavity. The transient results provided some valuable information in terms of the times required for the evolution of the natural convection process in the cavity.