Numerical and experimental characterization of a double-orifice synthetic jet actuator

A complete investigation of a doubleorifice synthetic jet actuator, focused on the device frequency response in terms of jet velocity, has been carried out. Numerical simulations have shown that, in many operation conditions, the flow within the actuator cavity can be considered as divided in two sub-volumes, each characterized by its own flow field. An analytical approach, based on the previous consideration, has allowed to obtain simple relationships for the three resonance frequencies and to provide further insights on the jets formation. The model has been validated through experimental tests carried out on two actuators manufactured in-house, having different geometrical and mechanical characteristics. Comparisons with the behavior of the twin singleorifice device have been discussed and useful considerations on the prediction of the actual formation of the synthetic jet are included .