COUPLED FLUID-STRUCTURAL CHARACTERISTICS OF ACTUATORS FOR FLOW-CONTROL

The characteristics of a typical flow control actuator design are disc ussed, The device is based on a resonating structure that interacts wi th a closed volume of fluid to create a concentrated jet through an ex it orifice. The resulting unsteady how through the orifice introduces viscous effects that are characterized by the Stokes parameter based o n the orifice diameter. An optimum operating Stokes parameter is then computed by matching this viscous dominated solution to an ideal, invi scid result. The actuator is modeled with a system of coupled equation s that describe its fluid-structural behavior. This model is compared to experimental results and is seen to predict time and frequency char acteristics well. Experimental data also show that, away from the exit orifice, the jet is self-similar and its intensity is also governed b y the Stokes parameter.