he oscillation characteristics of two planar opposed jets were studied by using high-speed camera
smoke wire visualization and hot-wire anemometry (HWA).The oscillation periods of two planar opposed jets at different nozzle separations and exit nozzle velocities were studied.The results showed two models of instabilities:streamwise quasi-periodic oscillation model and deflection oscillation model.The oscillation model was mainly streamwise quasi-periodic oscillation model at L<5H (where L was the nozzle separation and H was the nozzle slot height)
and it was mainly deflection oscillation model at L>5H.The deflection oscillation model had a stable period which decreased with increasing normalized nozzle separation.