Flow structure generated by two synthetic jets in a channel: Effect of phase and frequency

A three-dimensional computational model was developed to investigate the interaction of two synthetic jets with cross flow in micro-channel. An experimental validation of the formation of synthetic jet was presented at the same scale as those used in this numerical work. Good agreement was obtained between the experimental results and the numerical data. The numerical approach was then used to perform studies with the two jets being in-phase and 180°out-of-phase at various operating frequencies and diaphragm amplitudes with fixed jet Reynolds number. The addition of one synthetic jet was shown to achieve greater mixing of flow in the micro-channel than those with single synthetic jet. Velocity field obtained from 180°out-of-phase configurations show a distinct pattern of vortex formation which results in continuous mixing of the flow in the channel throughout the cycle. When the synthetic jet actuators were driven at different membrane frequencies and amplitudes, the main difference was the variation of the size and number of the vortices downstream and upstream of the office. The structure of the flow in the micro-channel is strongly dependent on the period of the oscillation of the membrane of the synthetic jet actuators.