Effects of actuation mode on plasma-induced spanwise flow oscillations

Two different plasma actuation strategies for producing near-wall flow oscillations, namely the burst-modulation and beat-frequency mode, are characterized with planar particle image velocimetry in quiescent air. Both concepts are anticipated to work as non-mechanical surrogates of oscillating walls aimed at turbulent flow drag reduction,...

Reducing turbulent convective heat transfer with streamwise plasma vortex generators

The effect of streamwise plasma vortex generators on the convective heat transfer of a turbulent boundary layer is experimentally investigated. A Dielectric Barrier Discharge (DBD) plasma-actuator array is employed to promote pairs of counter-rotating, streamwise-aligned vortices embedded in a well-behaved turbulent boundary layer over a flat...

Stall control by plasma actuators: Characterization along the airfoil span

A dielectric barrier discharge actuator (DBD) is considered and studied as a stall recovery device. The DBD is installed on the nose of a NACA0015 airfoil with chord × span 300 × 930 mm. The geometry of the exposed electrode has periodic triangular tips purposely designed for the case under study. Wind tunnel tests have been carried out over...

Plasma Actuation for Mitigation of Fluctuating Loads on Airfoils: An Experimental Study

Wind tunnel measurements are performed to investigate the potential for mitigation of aerodynamic load fluctuations on airfoils, as the main source of fatigue for wind turbines, using plasma actuators. The experiment consists of aerodynamic force measurements using six strain gauges and 2-component velocity measurements using particle image...

Conditioning of unsteady cross-flow instability modes using dielectric barrier discharge plasma actuators

In this study, experiments are performed towards the identification and measurement of unsteady modes occurring in a transitional swept wing boundary layer. These modes are generated by the interaction between the primary stationary and travelling cross-flow instabilities or by secondary instability mechanisms of the stationary cross-flow...

Effect of Local DBD Plasma Actuation on Transition in a Laminar Separation Bubble

This work examines the effect of local active flow control on stability and transition in a laminar separation bubble. Experiments are performed in a wind tunnel facility on a NACA 0012 airfoil at a chord Reynolds number of 130 000 and an angle of attack of 2 degrees. Controlled disturbances are introduced upstream of a laminar separation...

Experimental method to quantify the efficiency of the first two operational stages of nanosecond dielectric barrier discharge plasma actuators

A method to quantify the efficiency of the first two operational stages of a nanosecond dielectric barrier discharge (ns-DBD) plasma actuator is proposed. The method is based on the independent measurements of the energy of electrical pulses and the useful part of the energy which heats up the gas in the discharge region. Energy input is...

Diagnostics for characterisation of plasma actuators

The popularity of plasma actuators as flow control devices has sparked a flurry of diagnostic efforts towards their characterisation. This review article presents an overview of experimental investigations employing diagnostic techniques specifically aimed at AC dielectric barrier discharge, DC corona and nanosecond pulse plasma actuators....