Investigation of a jet in a cross flow using PIV

摘要

The effect of streamwise excitation on the mixing and velocity field of a jet in a cross flow is investigated or jet-to-cross flow velocity ratios of 0.33, 0.6, and 1.0 using the two-color PIV technique. The jet emanates from a square conduit and is manipulated by four piezoelectric actuators, one mounted algong each side of the jet conduit near the jet exit plane. Time-and phase-averaged cross stream and spanwise distributions of velocity and rms velocity fluctuations are also obtained. A novel approach is employed for processing of PIV images which makes it possible to distinguish between the jet fluid and the cross flow based on the size of the seeding particle. In addition, reactive Mie scattering images are used to assess the effect of excitation on molecular mixing. The present results show that manipulation of the upstream and downstream segments of the jet shear layer leads to diminution of the low-velocity domain in the wake of the jet, an increase in its penetration into the cross flow (up to 30