Modeling of Zero-Net Mass-Flux Actuators for Feedback Flow Control

The development of a fully compressible, coupled fluid-structure model of a zero-net mass-flux (ZNMF) actuator for flow control applications is presented. The actuator uses a piezoelectric bimorph diaphragm to synthesize a jet. The computational model couples a lumped element model for the deflection of the piezoelectric diaphragm with a fully compressible flow solver to model the actuator flow field. This model represents an extension of previous efforts that are restricted to periodic sinusoidal excitation waveforms. Here, the ZNMF behavior of the jet is enforced. However, the excitation waveform need not be periodic, as may be the case in feedback control applications. The ultimate goal of the effort is to couple the actuator with various flow fields to carry out high-fidelity feedback flow control simulations. The model is developed and validated using measurements of diaphragm deflection and jet exit velocity.