Flow disturbances depending on excitation frequency on a flat plate by a piezoceramic actuator

Abstract

Flow disturbances by a piezoceramic actuator were investigated to obtain physical insights on the streamwise vortex formation and excitation frequency effects on a piezoceramic actuator. Boundary-layer measurements in wind tunnel and flow visualization in water tunnel were carried out to explore flow disturbance. Findings revealed that streamwise vortex pair was formed in the moderate excitation frequency range, accompanied by low- and high-speed regions formation in the streamwise mean velocity field. U-turbulence intensity was tremendously increased in the high excitation frequency range. As a result, the formation of streamwise vortex pair was significantly influenced by excitation frequency and thus, the flow control purpose should be considered when constructing the proper design parameters for a piezoceramic actuator.