Delta Wing Flow Control Using Plasma Actuation

Experimental investigation was conducted to maximize delta-wing performance, by studying the active control of low aspect ratio delta wings at low Reynolds number, by means of leading-edge mounted dielectric barrier discharge (DBD) plasma actuation.

main objective

1. Enhance delta wing performance at low speeds (Re  75,000), using (DBD) plasma actuation.
2. Study the effect of actuation, study combined active (DBD actuator) and passive trailing edge (Gurney flap) control.
3. Investigation of the flowfield corresponding to conditions under which active control was most effective.

Details on the actuator

The actuator which will be used in this investigation for active flow control consists of two electrodes from tinned copper tapes, which are separated by an insulating material (three layers of Kapton tape) fig.1. The lower electrode is completely covered with the dielectric where as the upper electrode is exposed to the air.

Sufficiently high voltages running at 2-8 kHz at a maximum of 10kV peak-to-peak voltage supplied to the actuator causes the air to weakly ionize at the edges of the upper electrodes. It is generally assumed that the air is ionized in the strong electric field between upper and lower electrode and then accelerated towards the lower electrode in the negative cycle of the driving HV signal.

Results

Maximum normal force and lift enhancements were observed at pulse reduced frequencies of  F⁺≈ 1. It shows that post-stall C_N increases by about 20%. A smaller increase in C_{L, max} is also seen.