Convective-diffusive transport with chemical reaction in natural convection flows

A study of laminar natural convection flow over a semi-infinite vertical plate at constant species concentration is examined. The plate is maintained at a given concentration of some chemical species while convection is induced by diffusion into and chemical reaction with the ambient fluid. In the absence of chemical reaction, a similarity transform is possible. When chemical reaction occurs, perturbation expansions about an additional similarity variable dependent on reaction rate must be employed. Two fundamental parameters of the problem are the Schmidt number, Sc, and the reaction order, n. Results are presented for the Schmidt number ranging from 0.01 to 10 000 and reaction order up to 5. In the presence of a chemical reaction, the diffusion and velocity domains expand out from the plate. This results in a larger, less distinct convection layer.