DOUBLE DIFFUSION IN A POROUS CAVITY SATURATED WITH NON-NEWTONIAN FLUID

A numerical and theoretical study of double-diffusive natural convecti on within a rectangular porous cavity saturated by a non-Newtonian flu id and characterized by a power-law model is conducted. The conditions on the vertical walls are of a constant temperature and concentration , The theoretical method utilizes the pure scaling arguments to estima te, in an order-of-magnitude sense, the type of now and the heat and m ass transfer patterns that can develop in the enclosure. The results o btained using the scaling arguments are then verified by performing a series of numerical experiments, Numerical solutions for the flowfield , the temperature and concentration distributions, and the heat and ma ss transfer rates are obtained for a wide range of parameters. Results are presented for 50 less than or equal to Ra less than or equal to 5 00, 0 less than or equal to N less than or equal to 20, 0.1 less than or equal to Le less than or equal to 500, and 0.5 less than or equal t o n less than or equal to 1.6. The order-of-magnitude predictions for the overall heat and mass transfer rates and their respective domains of validity are shown to be in agreement with the results produced by discrete numerical experiments.