Micro-Piv Flow Measurements Near Singular Points Inside a Diamond-Shaped Cylinder Bundle

Abstract

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 PIV technique was employed to obtain the time-wise variations of both the velocity-vector and vorticity distributions. With the aid of LDV measurements, the Reynolds stress and power spectral distributions were also acquired. 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.