Oscillatory Motion of Natural Convection in Rectangular Cavity

Abstract

An oscillatory motion of the natural convection in a rectangular cavity has been studied both experimentally and analytically. Experiments were conducted mainly with the case that the hot and cold surfaces were set up as the upper and lower half wall of a side plate, and the other walls were insulated. Periodic oscillations of the hot and cold cell were found to exist by the flow visualization in the certain range of Rayleigh number. The influence of Prandtl number and aspect ratios of the cavity on the oscillation frequency were also examined. Unsteady two-dimensional equations, which govern the laminar natural convection, were solved numerically to simulate the oscillation. And the calculated flow patterns and oscillation frequency were fairly in good agreement with the experiments. From these fact, the adoptability of above numerical schemes to the other systems of the oscillations were also discussed.