In the present study an active flow control actuator is studied numerically using the CFD package Fluent
. A two-dimensional setup is chosen which corresponds to a cut through a real configuration that was studied experimentally by Lachowicz
.  and called ”Jet and Vortex Actuator” (JaVA) because of its ability to produce such completely different flow regimes when its actuation frequency and amplitude are changed. Three cases are selected for validation of the simulations. A vortex mode, a verticaljet and a wall-jet mode. Our simulations yield the
flow field, whereas only time-averaged data are available from literature. Thus, our simulations provide extra details of the flows through the gaps intended for a better understanding of the actuator flow. Qualitative and quantitative comparisons of the time-averaged data with the experiments are very encouraging. Especially, the different flow regimes appear for the same parameters as in the experiments.