Development of a prediction model for synthetic jets in quiescent conditions

A prediction model of the performance of circular synthetic jets in quiescent conditions is developed using both dimensional and quantitative analyses. This model provides analytical relations between the performance parameters (both dimensional and non-dimensional) and the operating parameters of synthetic jet actuators. The model is validated by a systematic numerical approach using 42 laminar flow cases which cover the dimensionless stroke length in the range of 1.13<L<4.46 and the Reynolds number in the range of 104<Re<3050. The peak velocity and mass flow rate at the orifice exit predicted with the model coincide with the simulation results. And the predicted exit momentum flux rate and total circulation are also in good agreement with the simulation results for L less than 3.5. The discrepancy at larger stroke lengths is caused by the fact that in the model the space-averaged velocity at the orifice exit plane based on the mass conservation consideration is used to estimate the exit momentum flux rate and total circulation. A study of the velocity variation at the orifice exit shows that the validity of this model can be extended to larger stroke lengths by introducing adequate correction factors that account for the spatial variations of velocity due to changing actuator operating parameters.