Mechanism of flow separation control using plasma actuation

The mechanism of flow separation control was investigated experimentally and computationally using pulse-modulated dielectric barrier discharge (DBD) plasma actuation on a stalled flat plate airfoil at a Reynolds number of 3000. Load measurements were complimented with two-dimensional phase-averaged particle image velocimetry performed in the flowfield above the airfoil. A parametric study was carried out where the pulse-modulation frequency, duty cycle, and peak plasma body-force were varied. The two-dimensional Navier-Stokes equations, with no turbulence modeling, were solved directly using a commercial flow solver and a simple but satisfactory heuristic DBD plasma body-force model was incorporated. The overall experimental trends were well predicted by the computations, where the frequencies that produced the largest increases in lift coefficient excited bluff-body shedding at a frequency corresponding approximately to its unforced sub-harmonic. At non-dimensional frequencies most effective for increas...

[1]  F. Browand,et al.  Vortex pairing : the mechanism of turbulent mixing-layer growth at moderate Reynolds number , 1974, Journal of Fluid Mechanics.

[2]  Chih-Ming Ho,et al.  Subharmonics and vortex merging in mixing layers , 1982, Journal of Fluid Mechanics.

[3]  B. Nishri,et al.  Effects of Periodic Excitation on Turbulent Flow Separation from a Flap , 1998 .

[4]  Chih-Ming Ho,et al.  Perturbed Free Shear Layers , 1984 .

[5]  Israel J Wygnanski,et al.  Active management of naturally separated flow over a solid surface. Part 1. The forced reattachment process , 2004, Journal of Fluid Mechanics.

[6]  A. Roshko,et al.  On density effects and large structure in turbulent mixing layers , 1974, Journal of Fluid Mechanics.

[7]  Thomas McLaughlin,et al.  Parameterization of Temporal Structure in the Single Dielectric Barrier Aerodynamic Plasma Actuator , 2006 .

[8]  Christopher L. Rumsey,et al.  Summary of the 2004 Computational Fluid Dynamics Validation Workshop on Synthetic Jets , 2006 .

[9]  Ari Glezer,et al.  Evolution of stream wise vortices and generation of small-scale motion in a plane mixing layer , 1991, Journal of Fluid Mechanics.

[10]  Subcritical Pipe Flow Transition Control Using Dielectric Barrier Discharge Plasma Actuators , 2009 .

[11]  Yannick Hoarau,et al.  Organized modes and the three-dimensional transition to turbulence in the incompressible flow around a NACA0012 wing , 2003, Journal of Fluid Mechanics.

[12]  Keith B. Paschal,et al.  Experimental Investigation of Separation Control Part 2: Zero Mass-Flux Oscillatory Blowing , 2006 .

[13]  I. Wygnanski,et al.  On the periodically excited plane turbulent mixing layer, emanating from a jagged partition , 2007, Journal of Fluid Mechanics.

[14]  Peter A. Monkewitz,et al.  Influence of the velocity ratio on the spatial instability of mixing layers , 1982 .

[15]  Israel J Wygnanski,et al.  Active management of naturally separated flow over a solid surface. Part 2. The separation process , 2004, Journal of Fluid Mechanics.

[16]  C. O. Paschereit,et al.  Plasma Flow Control on Low Aspect Ratio Wings at Low Reynolds Numbers , 2010 .

[17]  Kwing-So Choi,et al.  Control of unsteady flow separation over a circular cylinder using dielectric-barrier-discharge surface plasma , 2009 .

[18]  Israel J Wygnanski,et al.  On the effect of initial conditions on the two dimensional turbulent mixing layer , 1978 .

[19]  Wei Shyy,et al.  Flapping and flexible wings for biological and micro air vehicles , 1999 .

[20]  C. R. Smith,et al.  Vortex Interactions with Walls , 1994 .

[21]  Israel J Wygnanski,et al.  Effect of Leading-Edge Curvature on Airfoil Separation Control , 2003 .

[22]  Jinhee Jeong,et al.  On the identification of a vortex , 1995, Journal of Fluid Mechanics.

[23]  Christian Oliver Paschereit,et al.  Dielectric Barrier Discharge Flow Control at Very Low Flight Reynolds Numbers , 2008 .

[24]  Luis P. Bernal,et al.  Streamwise vortex structure in plane mixing layers , 1986, Journal of Fluid Mechanics.

[25]  Andrew Ooi,et al.  On the coherent structures and stability properties of a leading-edge separated aerofoil with turbulent recirculation , 2011, Journal of Fluid Mechanics.

[26]  Chih-Ming Ho,et al.  Unsteady aerodynamics and flow control for flapping wing flyers , 2003 .

[27]  T. Corke,et al.  SDBD plasma enhanced aerodynamics: concepts, optimization and applications , 2007 .

[28]  Christopher L. Rumsey,et al.  Prediction of high lift: review of present CFD capability , 2002 .

[29]  Israel J Wygnanski,et al.  The control of flow separation by periodic excitation , 2000 .

[30]  T. Mueller,et al.  AERODYNAMICS OF SMALL VEHICLES , 2003 .