Abstract:
Experimental investigation of natural convection in a long vertical annulus closed at the top and opened at the bottom is presented. Numerical simulation is performed using the restricted domain model and extended domain model. The outer wall and top wall of inner cylinder are insulated. The outer wall of outer cylinder is cooled with the following speeds: 2.9, 5.7, 8.6m/s. And the corresponding Grashof number is 9.8×10
6, 3.9×10
6, and 8.3×10
5. The discrepancy between the numerical and experimental results is small when Grashof number is less than 10
6 and becomes bigger when Grashof number exceeds 10
6.