MAXIMUM DENSITY EFFECTS ON NATURAL-CONVECTION OF MICROPOLAR FLUIDS BETWEEN HORIZONTAL ECCENTRIC CYLINDERS

Natural convection heat transfer of micropolar fluids near the maximum density in a horizontal eccentric annulus is studied numerically. The governing equations, in terms of vorticity, stream function and tempe rature, are expressed in a body-fitted coordinate system, and solved n umerically by the finite difference method with the modified strongly implicit procedure. The main objective is to investigate the differenc es of fluid dow and temperature fields for various eccentricities e wi th Rayleigh numbers Ra ranging from 671 to 5 x 10(4) and inversion par ameter Theta(m) variations between 0 and 1. The micropolar parameter D elta is varied from 0 to 1. The results indicate that both inversion p arameter and eccentricities have a strong effect on the flow structure and heat transfer rate in the annulus. In comparison to a Newtonian f luid, the mean Nusselt number is reduced for a micropolar fluid. Moreo ver, good agreement is obtained with the present numerical results and the available experimental data. (C) 1998 Elsevier Science Ltd.