No abstract

In this work, an experimental study on the effectiveness of the multi-tip geometry for plasma actuators is presented for a separation control problem. The multi-tip geometry consists in a periodical series of triangular tips on the active electrode edge. Both DC corona and AC Dielectric Barrier Discharge (DBD) actuators are considered and their performances are compared. The plasma actuators are installed on the leading edge of a NACA 0015 airfoil and tested at high angles of attack in the wind tunnel for freestream velocities in the range 5 – 20 m/s. The flow control mechanisms are briefly discussed. Force measurements are performed by means of an aerodynamic balance and the force coefficients are derived. Electrical measurements are also performed, to quantify the consumed power. The actuators effectiveness is evaluated through some suitable performance parameters. In general, a properly chosen multi-tip geometry is found to be more performing than traditional straight edge configurations, both for coronas and DBDs. Furthermore, corona actuators give comparable aerodynamic performance with respect to DBDs, but they require an order of magnitude lower power

No abstract

No abstract

Abstract. This work presents an experimental investigation about the effects of triangular tips on the active electrodes of plasma actuators. The tests are performed on two sets of actuators, corona and DBD, parameterized by means of the tip sharpness and the tips number per unit length. A total number of 30 actuators is considered. The devices are evaluated on the basis of the far field ionic wind velocity, that has been chosen as a representative test common to both kinds of actuator. The dataset includes velocity profiles and maps, that can be integrated to give mass flows and electromechanical efficiencies. Some results are also presented in the parameter space defined by tip sharpness and tips number per unit length: this gives the chance of defining optimal electrode shapes within each set. In general, the longitudinal velocity of the gas increases downstream of the tips in all the actuators tested, but the velocity field is modified to different extents in the two kinds of actuators, and is more complicated for the DBDs than for the coronas. The tips also increase the efficiency of all the actuators, particularly for the corona set, where even the stability is remarkably improved.