Abstract
The laminar-turbulent transition of a mixing layer induced by oscillating flat plates at an exit of a two-dimensional nozzle was experimentally investigated. The mixing layer was formed between the jet which issued from the nozzle and the surrounding quiescent fluid. The plates oscillated vertically in relation to the mean flow. The oscillation frequency magnitude was quite smaller than the fundamental frequency of the velocity fluctuation. The mixing layer was more diffused due to an increase of the oscillating frequency from 5Hz to 15Hz. The growth of turbulence was promoted due to the plate oscillation. The increase of frequency, however, did not affect the growth of turbulence. Fluctuating energy production and convection rates that contribute to the streamwise and normal fluctuating velocities became maximum at different streamwise stations. The stations did not correspond to the respective positions where the fluctuating velocity became maximum in the streamwise component, although it corresponded in the normal component.
