Studies of the Flow Fields Created by Single Vertical Jets Directed Downwards upon a Horizontal Surface

摘要

The velocity and temperature conditions in the space surrounding a single nozzle discharging hot gas vertically downwards on to a horizontal surface have been studied. Except at very low exit velocities, the amount of recirculation to an intake situated on the axis of the jet is small. Within limits, the dynamic head at ground level at a point away from the axis is independent of the height of the nozzle above the ground. These limits are decided by the spread of the jet before it reaches the ground, and by the lateral extent of the jet before it separates and rises from the ground.