Controlling Separation on a Simulated Compressor Blade Using Vortex-Generator Jets

Flow control using vortex-generator jets has been used to control a separating boundary layer on the surface of a flat plate in the presence of a pressure distribution equaling that on the suction surface of a compressor blade. A parametric study has been performed in which the skew angle and jet velocity of steady jets have been varied. In addition to steady blowing, the jets have been pulsed over a range of reduced frequency from 0.5 to 7.0. Steady blowing with a jet velocity greater than the inlet flow velocity was found to delay separation on the surface of the flat plate and reduce the loss coefflcient of an equivalent cascade blade by 36 %, relative to the unactuated case. This jet velocity is equivalent to an injected mass flow rate of 0.13 % of the inlet mass flow rate. With pulsed blowing, the same loss reduction was achieved over the unactuated case using 40% less mass flow. This loss reduction, however, required a reduced frequency greater than 6.0 and a peak jet velocity equal to 1.5 times the inlet flow velocity. This corresponds to a jet Mach number in a real compressor of 1.125, pulsing at more than 180 kHz.

[1]  K. McManus,et al.  Pulsed vortex generator jets for active control of flow separation , 1994 .

[2]  I. Milanovic,et al.  Fluid Dynamics of Highly Pitched and Yawed Jets in Crossflow , 2004 .

[3]  S. Honami,et al.  Behaviors of the Laterally Injected Jet in Film Cooling: Measurements of Surface Temperature and Velocity/Temperature Field Within the Jet , 1992 .

[4]  J. Denton.  Loss Mechanisms in Turbomachines , 1993 .

[5]  Ralph J. Volino.  Separation Control on Low-Pressure Turbine Airfoils Using Synthetic Vortex Generator Jets , 2003 .

[6]  Mohamed Gad-el-Hak,et al.  Flow Control: The Future , 2001 .

[7]  Farrukh S. Alvi,et al.  Use of High-Speed Microjets for Active Separation Control in Diffusers , 2006 .

[8]  Hyoun-Woo Shin,et al.  Design and Test of an Ultralow Solidity Flow-Controlled Compressor Stator , 2005 .

[9]  Shinji Honami,et al.  Behavior of the Laterally Injected Jet in Film Cooling: Measurements of Surface Temperature and Velocity/Temperature Field Within the Jet , 1994 .

[10]  A. Gross,et al.  Numerical Investigation of Low Pressure Turbine Blade Separation Control , 2003 .

[11]  Paolo Graziosi,et al.  Characterization of Steady Blowing for Flow Control in a Hump Diffuser , 2005 .

[12]  Hyoun-Woo Shin,et al.  Design and Test of an Ultra-Low Solidity Flow-Controlled Compressor Stator , 2004 .

[13]  Dennis E. Culley,et al.  Active Flow Separation Control of a Stator Vane Using Surface Injection in a Multistage Compressor Experiment , 2003 .

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

[15]  Laura C. Hansen,et al.  Flow measurements of vortex generator jets in separating boundary layer , 2006 .

[16]  Z. U. Khan,et al.  ON VORTEX GENERATING JETS , 2000, Proceeding of First Symposium on Turbulence and Shear Flow Phenomena.

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

[18]  J. Bons,et al.  Turbine Separation Control Using Pulsed Vortex Generator Jets , 2000 .

[19]  Louis N. Cattafesta,et al.  Numerical Study of Resonant Interactions and Flow Control in a Canonical Separated Flow , 2005 .

[20]  F. G. Howard,et al.  Control of low-speed turbulent separated flow using jet vortex generators , 1992 .

[21]  H. Johari,et al.  Effects of Pulsing on a Vortex Generator Jet , 2003 .

[22]  K. P. Garry,et al.  The effect of skewing on the vorticity produced by an airjet vortex generator , 1998, The Aeronautical Journal (1968).

[23]  Mike Hirst,et al.  ADVACT an European Program for Actuation Technology in Future Aero-Engine Control Systems , 2006 .

[24]  M. Amitay,et al.  Aerodynamic Flow Control over an Unconventional Airfoil Using Synthetic Jet Actuators , 2001 .

[25]  J. Bons,et al.  The Fluid Dynamics of LPT Blade Separation Control Using Pulsed Jets , 2001 .

[26]  Hermann F. Fasel,et al.  Numerical Investigation of Low-Pressure Turbine Blade Separation Control , 2005 .

[27]  James P. Johnston,et al.  Streamwise vortex production by pitched and skewed jets in a turbulent boundary layer , 1991 .

[28]  J. Bons,et al.  Control of Low-Pressure Turbine Separation Using Vortex-Generator Jets , 2002 .

[29]  John D. Denton,et al.  The 1993 IGTI Scholar Lecture: Loss Mechanisms in Turbomachines , 1993 .