Separation Control Using Oscillatory Blowing On 3-D Finite Wings
Abstract
Previous work on 2-D airfoils has shown repeatedly that low amplitude, oscillatory blowing can delay separation and enhance lift over a wide range of Reynolds and Mach numbers. Recent experiments with 3-D delta and lambda profile finite wings have demonstrated several consistent results, including: 1) the most effective location for unsteady forcing is near the point of separation, 2) the optimum reduced frequency for the oscillations is near fc/U=1, 3) the amplitude of the oscillations required for effective separation control is about two orders of magnitude lower than that for steady blowing. Measurements of velocity fields, surface pressure, and direct force balance measurements, with and without oscillatory forcing from the leading edge and low oscillatory momentum coefficients near 0.01%, have suppressed separation and increased lift for both 2-D and 3-D wings. This suggests that oscillatory blowing influences the structure of leading edge vortices to maintain high pressure coefficients and prevent stall in 3-D finite swept airfoils.
- Publication:
-
APS Division of Fluid Dynamics Meeting Abstracts
- Pub Date:
- November 1998
- Bibcode:
- 1998APS..DFD..FB09H