PIV measurements of a zero-net-mass-flux jet in cross flow

Particle image velocimetry (PIV) is used to study a circular zero-net-mass-flux (ZNMF) jet in cross flow (JICF). ZNMF jets are formed by using the working fluid of the environment into which the jet is issuing without net transfer of fluid mass into the environment from the ZNMF jet system during one period of oscillation. Two ZNMF-JICF, which are characterized by Re-j=1,240, R=4.6, St=0.016 and Re-j=2,960, R=7, St=0.014, are investigated in this study. Phase-averaged in-plane velocity and out-of-plane vorticity vector fields in the)et near field are presented and the time-dependent volume flow is calculated to study the structure of the jets. Ensemble-averaged in-plane velocity data in the jet far field were determined to study the mean jet structure. The ensemble-averaged vector fields are used to determine jet trajectory and the velocity variation along the trajectory. These results are discussed and compared to continuous and pulsed jets in cross flow.