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The purpose of this paper is to propose a simple model for plasma generation and effect on fluids at atmospheric pressure. Experiments are conducted using a wire-to-wire corona discharge actuator in a subsonic boundary layer flow. Velocity gains of several metres per second are observed. A quasi-2D numerical model of the discharge is proposed and explains the creation of two corona discharges around the electrodes. A one-way approach of the plasma aerodynamics coupling gives access to the ionic wind. It is confirmed that the actuator accelerates the flow from the anode to the cathode. Order of magnitudes of the ionic wind and flow velocity profiles are close to experiments. A first attempt to perform a 2D simulation of the wire-to-wire discharge is presented as the starting point of future works.

NOMENCLATURE a speed of sound, ms -1 c blade chord, m u′ 2 root mean square of velocitiy longitudinal component v′ 2 root mean square of velocitiy spanwise component w′ 2 root mean square of velocitiy vertical component M WT Mach number of wind-tunnel flow, M WT = V WT /a M MR Mach number of blade tip in hover, main rotor, M MR = (ΩR) MR /a M TR Mach number of blade tip in hover, tail rotor, M TR = (ΩR) TR /a R blade radius, m α S rotor shaft angle-of-attack α fus fuselage angle-of-attack μ advance ratio M WT /M MR ψ MR main rotor azimuth angle (0° = reference blade above the fuselage) Ω rotor rotational frequency, rad/s ABSTRACT The GOAHEAD (Generation of an Advanced Helicopter Experimental Aerodynamic Database for CFD code validation) consortium was created in the frame of an EU-project in order to create an experimental database for the validation of 3D-CFD and comprehensive aeromechanics methods for the prediction of unsteady viscous flows. This included the rotor dynamics for complete helicopter configurations, i.e. main rotor -fuselage -tail rotor configurations with emphasis on viscous phenomena like flow separation and transition from laminar to turbulent flow. The wind tunnel experiments have been performed during two weeks in the DNW-LLF on a Mach-scaled model of a modern transport helicopter consisting of the main rotor, the fuselage, control surfaces and the tail rotor. For the sake of controlled boundary conditions for later CFD validation, a closed test section has been used. The measurement comprised global forces of the main rotor and the fuselage, steady and unsteady pressures, transition positions, stream lines, position of flow separation, velocity profiles at the test section inlet, velocity fields in the model wake, vortex trajectories and elastic deformations of the main and tail rotor blades.

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