Dual Solutions for Steady Natural Convection of Air in Horizontal Cylindrical Annulus

Title & Authors
Dual Solutions for Steady Natural Convection of Air in Horizontal Cylindrical Annulus
Yu, Ju-Sik;

Abstract
Dual solutions for steady natural convection of air between two horizontal concentric cylinders are numerically investigated in the range of $D_i$/TEX>/L(=diameter of inner cylinder/gap width)$\small{\leq}$10. It is found that, when the Rayleigh number based on the gap width exceeds a certain critical value, a new flow pattern forming two counter-rotating eddies in the half of the annulus can be realized, which is different from the crescent-shaped flow commonly observed. In the new flow pattern, the fluid near the top of the hot inner cylinder moves downward. This solution is found for D$\small{_{i}}$/L.geq.0.3, but not for$D_i$/TEX>/L$\small{\leq}$0.2. As $D_i$/TEX>/L increase, the critical Rayleigh number is decreased, and tends to a finite limit.t.
Keywords
Thermal Instability;Cellular Convection;Critical Rayleigh Number;Dual Solutions;
Language
Korean
Cited by