Physics and Improved Simulations for Computational Modeling of Synthetic Jets

With the rise of active flow control techniques several approaches of flow reattachment have been studied, including the use of direct momentum injection through a zero-net mass flow synthetic jet. The focus of this paper is to further understand the role of turbulence in the physics of synthetic jets and the sensitivity of external crossflow on the prediction of the jet and its downstream behavior while in cross flow. Computational results are correlated with recent experimental data obtained by the U.S. Army. The full actuator geometry is computationally modeled and to develop unsteady and phase-averaged boundary conditions at the jet/outer mold line interface at the relevant spatial and temporal levels. This study also considers the effect of turbulence model, as well as the associated turbulent quantities, and their influence in the prediction of the local synthetic jet flowfield in cross flow. Results indicate that turbulent fluctuations in three-dimensional flows with large eddy simulation wakes are required to predict the jet interactional effects. The external crossflow has a significant impact on the magnitude of the turbulent characteristics, but the trends observed in experiments are captured with the additional of turbulence in the jet.