Active Flow Control Strategy of Laminar Separation Bubbles Developed over Subsonic Airfoils at Low Reynolds Numbers

A computational parametric study designed to examine the plausibility of an external body force generated by active means, such as a plasma actuator, as a way of controlling a Laminar Separation Bubble (LSB) over an airfoil at low Reynolds numbers was conducted. Computational Fluid Dynamics (CFD) was employed to characterize the effect that a body force, localized to a small region tangent to the airfoil surface, might have on an LSB. In this study, the effects of altering the strength and location of the “actuator” on the size and location of the LSB and on the aerodynamic performance of the airfoil were observed. It was found that the body force, when properly located and with sufficient magnitude, could effectively eliminate the LSB. Additionally, it was found that by eliminating the LSB, the aerodynamic efficiency of the airfoil could be improved by as much as 60%. Thus, it was determined that such a system may indeed be an effective measure of reducing or eliminating the negative effects associated with LSBs at low Reynolds numbers, making the strategy an excellent candidate for future experimental research regarding this topic.

[1]  Eric J. Jumper,et al.  Mechanisms and Responses of a Single Dielectric Barrier Plasma Actuator: Plasma Morphology , 2004 .

[2]  Jamey Jacob,et al.  Numerical Simulations of Plasma Based Flow Control Applications , 2005 .

[3]  Ulrich Rist,et al.  Control of Laminar Separation Bubbles Using Instability Waves , 2006 .

[4]  Thomas Corke,et al.  Numerical Simulation of Aerodynamic Plasma Actuator Effects , 2005 .

[5]  E. Matlis,et al.  Controlled Experiments on Instabilities and Transition to Turbulence on a Sharp Cone at Mach 3.5 , 2003 .

[6]  T. McLaughlin,et al.  Mechanisms and Responses of a Single Dielectric Barrier Plasma , 2003 .

[7]  S.J. Schreck,et al.  Horizontal Axis Wind Turbine Blade Aerodynamics in Experiments and Modeling , 2007, IEEE Transactions on Energy Conversion.

[8]  O. N. Ramesh,et al.  Laminar separation bubbles: Dynamics and control , 2007 .

[9]  Wei Shyy,et al.  Modeling of glow discharge-induced fluid dynamics , 2002 .

[10]  E. Jumper,et al.  Mechanisms and Responses of a Dielectric Barrier Plasma Actuator: Geometric Effects , 2004 .

[11]  D. J. Mckinzie,et al.  Control of laminar separation over airfoils by acoustic excitation , 1989 .

[12]  Thomas Corke,et al.  DNS Modeling of Plasma Array Flow Actuators , 2001 .

[13]  Christian Bak,et al.  Observations and hypothesis of double stall , 1999 .

[14]  Eric J. Jumper,et al.  Potential Flow Model for Plasma Actuation as a Lift Enhancement Device , 2005 .

[15]  Thomas Corke,et al.  Plasma Actuators for Separation Control of Low-Pressure Turbine Blades , 2006 .

[16]  Subrata Roy,et al.  Modeling Surface Discharge Effects of Atmospheric RF on Gas Flow Control , 2005 .

[17]  Guillermo Artana,et al.  Steady control of laminar separation over airfoils with plasma sheet actuators , 2006 .