Abstract
Buoyancy-driven exchange flows of helium-air through horizontal and inclined small openings were investigated. Exchange flows may occur following the opening of a window for ventilation, when fire breaks out in a room, as well as when a pipe ruptures in a high temperature gas-cooled nuclear reactor. The experiment in this paper was carried out in a test chamber filled with helium and the flow was visualized using the smoke wire method. The flow behavior was recorded by a high-speed camera combined with a computer system. The image of the flow was transferred to digital data, and the flow velocity was measured by PTV software. From the experiment, it is clear that the inclination angle for the maximum flow rate is 30 degree.
