This paper shows the time-averaged effect of synthetic jet and plasma actuators on flow over a representative two-dimensional rotorcraft tail boom for delaying flow separation and, therefore, reducing pressure drag, whereas previous studies have evaluated these flow control devices on a circular cylinder. The percentage of pressure drag reduction is used to evaluate the effectiveness of these two unique actuators for varied applied voltage under device independent conditions such as actuator position and flow velocity. Two non-dimensional parameters were used to evaluate the effect of the actuators: coefficient of momentum (Cμ) and non-dimensional surface distance between the location of the actuator and the flow separation point (SDTB). Both actuation techniques beneficially affect the pressure distribution by decreasing the pressure near the location of the actuators and increasing the pressure in the separated flow region. Contour plots displaying the variation of the percentage of pressure drag reduction as Cμ and SDTB vary illustrate optimal operating conditions based on these parameters. While this study is not a one-to-one comparison of these two devices, the results clearly show that, under the same external flow conditions, synthetic jet actuators have a global effect where as plasma actuators have a local effect both reducing the pressure drag up to 40% and 45%, respectively.
Flow Control Using Synthetic Jet and Plasma Actuators on a Rotorcraft Tail Boom Model
Published Online: November 11, 2009
Abstract