EFFECT OF TAB GEOMETRY ON SONIC JET CHARACTERISTICS

摘要

The effect of vortex generators, in the form of small rectangular tabs projecting normally into the flow at the nozzle exit, on the mixing characteristics of axisymmetric sonic jets is investigated experimentally. The streamwise vortices introduced by the tabs lead to a more rapid decay of the centre line pressure. Also, the tabs were found to weaken the shocks in the jet core significantly. The tabs are most effective for nozzles operating at underexpansion than correct expansion. Further, for the same projected area, length of the tab is more effective in enhancing the mixing than its width. As high as 80 per cent reduction in core length was achieved with tabs in the present study.