FLOW CHARACTERISTICS NEAR THE 'INTERFERENCE KNOT POINT' INSIDE A DIAMOND-SHAPED CYLINDER BUNDLE

摘要

The interaction between the oscillating jet and the wedge produces a fluctuating flow field outside the jet which in turn affects the motion of the jet. However, microscopic evidence of these phenomena remains undisclosed. In the present study, an optical system-operated P1V technique was employed to obtain the time-wise variations of both the velocity-vector and vorticity distributions near an "interference knot point" inside a diamond-shaped cylinder bundle. In conclusion, the micro PIV measurements have for the first time disclosed the location and flow process characteristics of the edge-tone source. In addition, the micro flow behavior of reciprocating migration of the conjunct separation vortex pair over the rear edge of the third-row cylinder is confirmed as the mechanism of flip-flow oscillations induced by the edge tone phenomenon.