Prediction of active flow control performance on airfoils and wings

Abstract A numerical investigation of active flow control, which can offer significant improvements to aircraft wing, helicopter and wind-turbine rotor performance by suppressing detrimental effects of separated flow, is presented. Numerical simulations of pulsating jet flow control applied on airfoils and wings at low speed, high Reynolds number turbulent flow and fixed angles of incidence are carried out. Pulsating jet active flow control is applied as a surface boundary condition and the flow is time-dependent. It was found that fine grid resolution is required to capture the pulsating jet and its interaction with the boundary layer. Efficient, implicit, time-accurate numerical methods for unsteady RANS of incompressible flow are used to overcome the stringent stability limitations imposed by small grid spacing. A widely tested one-equation turbulence model is used for the prediction of the complex, unsteady flowfields. It is found that active flow control can enhance aerodynamic performance by reducing the adverse effects of separated flow. The effect of pulsation frequency, and jet exit velocity on flow control is investigated.

[1]  D Joslin Ronald,et al.  Aerodynamic Performance of an Active Flow Control Configuration Using Unstructured-Grid RANS , 2001 .

[2]  K. W. McAlister,et al.  Suppression of Dynamic Stall by Steady and Pulsed Upper-Surface Blowing , 1998 .

[3]  M. S. Chandrasekhara,et al.  Compressible dynamic stall control using a shape adaptive airfoil , 1999 .

[4]  Sivaguru S. Ravindran,et al.  Active Control of Flow Separation Over an Airfoil , 1999 .

[5]  John A. Ekaterinaris,et al.  NUMERICAL SIMULATION OF INCOMPRESSIBLE TWO-BLADE ROTOR FLOWFIELDS , 1998 .

[6]  P. Spalart.  A One-Equation Turbulence Model for Aerodynamic Flows , 1992 .

[7]  John A. Ekaterinaris,et al.  Numerical Investigations of Dynamic Stall Active Control for Incompressible and Compressible Flows , 2000 .

[8]  Stuart E. Rogers,et al.  Steady and unsteady solutions of the incompressible Navier-Stokes equations , 1991 .

[9]  John A. Ekaterinaris,et al.  Computation of oscillating airfoil flows with one- and two-equation turbulence models , 1994 .

[10]  A. Glezer,et al.  The formation and evolution of synthetic jets , 1998 .

[11]  I. Wygnanski,et al.  Delay of Airfoil Stall by Periodic Excitation , 1996 .

[12]  Fei-Bin Hsiao,et al.  Forcing level effects of internal acoustic excitation on the improvement of airfoil performance , 1992 .

[13]  Miguel R. Visbal,et al.  Numerical investigation of synthetic-jet flowfields , 1999 .

[14]  Ahmed A. Hassan,et al.  Effects of zero-mass 'synthetic' jets on the aerodynamics of the NACA-0012 airfoil , 1997 .

[15]  P. Roe.  Approximate Riemann Solvers, Parameter Vectors, and Difference Schemes , 1997 .

[16]  Xi-Yun Lu,et al.  POST-STALL LIFT ENHANCEMENT ON AN AIRFOIL BY LOCAL UNSTEADY CONTROL Part II. Mode Competition and Vortex Dynamics , 1997 .

[17]  Mohamed Gad-el-Hak,et al.  Separation control - Review , 1991 .

[18]  A. Seifert,et al.  Oscillatory Control of Separation at High Reynolds Numbers , 1999 .

[19]  M. S. Chandrasekhara,et al.  Compressible dynamic stall control - A comparison of different approaches , 1999 .

[20]  A. Chorin.  A Numerical Method for Solving Incompressible Viscous Flow Problems , 1997 .

[21]  Charles Merkle,et al.  Time-accurate unsteady incompressible flow algorithms based on artificial compressibility , 1987 .

[22]  D. C. McCormick,et al.  BOUNDARY LAYER SEPARATION CONTROL WITH DIRECTED SYNTHETIC JETS , 2000 .

[23]  I. Wygnanski,et al.  Oscillatory Blowing: A Tool to Delay Boundary-Layer Separation , 1993 .

[24]  Jeonghwan Ko,et al.  Flow Separation Control Via Synthetic J&t Actuation , 2000 .

[25]  Israel J Wygnanski,et al.  Parameters affecting dynamic stall control by oscillatory excitation , 1999 .