NATURAL-CONVECTION IN HORIZONTAL ECCENTRIC ANNULI - NUMERICAL STUDY

The fluid dynamic and thermal fields in a two-dimensional annulus between horizontally eccentric cylinders (R(o) / R(in) = 2.36) are numerically studied in laminar steady conditions. The Navier-Stokes equations with Boussinesq approximation are solved for a typical fluid with Pr = 0.71, 0.53 x 10(4) less-than-or-equal-to Ra(L) less-than-or-equal-to 8.27 x 10(4), and a wide eccentricity range (0 less-than-or-equal-to e < 1). The governing equations are written in primitive variable form to avoid the enforcement of the additional integral condition for the pressure single valuedness. The horizontal eccentricity of the inner cylinder gives, in contrast with known numerical results, a nonzero azimuthal flow rate in the channel between the two cylinders and substantially alters the thermal field and the geometry of the plume. Comparisons with available numerical and experimental results for concentric and horizontally eccentric configurations are presented and discussed.