Flow separation is an important phenomenon to consider when designing airplane wings, stabilizers, and other fluid dynamics applications such as ground vehicles and internal diffuser flows. When unattended flow separation can lead to increase in drag, stall and energy losses, up to a loss of controlled flight. It is therefore desirable to have actuators and associated control techniques that can mitigate this phenomenon, a research domain collectively known as flow control.
In this work we characterize the performance of a novel plasma actuator, termed as the cathodic arc actuator (CAA). The CAA operates by igniting a cathodic-arc discharge between two closely spaced flush electrodes. The discharge time evolution was experimentally characterized using several techniques including: fast photography, spectroscopy, particle image velocimetry (PIV), as well as direct measurement of thrust. In the first part of the talk we present a time dependent 0-D thrust model of the CAA interaction with ambient air. The model is shown to be in excellent agreement with measurement results.
In the second part of the talk we present results from a flow control experiment, where the CAA is embedded in an aerodynamic model and operated inside a low speed wind tunnel. Hot wire anemometry and optical-oil based techniques were used to measure the influence of actuator operation on the flow. A procedure for selecting aerodynamic model parameters for such experiments will be discussed as well.
