A numerical finite-difference study of the oscillatory behavior of vertically vented compartments

A numerical finite-difference study has been carried out in two and three dimensions for turbulent buoyant flow in a square compartment with floor and ceiling vents. A volumetric heat source is located either at the center of the floor or at the lower left corner of the compartment. Oscillatory behaviors have been found in the flow and temperature fields for the cases with center heat source, while for cases with heat source at the lower left corner, oscillations only occur during the initial transient period and are thereafter quickly damped out. The physical origin of these oscillations is noted. Results for one of the cases are also shown in terms of the effect of heat source strength on the frequency of oscillations.