Flow Control Over Sharp-Edged Wings
Final rept. 1 Mar 2004-31 Mar 2007
VIRGINIA POLYTECHNIC INST AND STATE UNIV BLACKSBURG DEPT OF ENGINEERING SCIENCE AND MECHANICS
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Wings swept by 30 to 40 degrees with sharp leading edges are today very common on flghter aircraft. There is very little work devoted to the understanding of the aerodynamics of such wings. The problem is That such wings may be able to sustain attached flow, even if their tip vortices are broken down, or stall like two-dimensional wings. The aerodynamics of such wings were studied and investigated experimentally. Pressure distributions and velocity fields were obtained in a wind tunnel and a water tunnel. The effectiveness of leading-edge control of the flow over such wings was explored. Oscillating mini-flaps and pulsed jets along the leading edge were employed. The results indicate that two-D-like vortices are periodically generated and shed. It was also discovered that an underline feature of the flow, a streamwise vortex is periodically activated, penetrating the separated flow, eventually emerging downstream of the trailing edge of the wing. The results indicate that significant increases in tilt can be achieved in the average, by managing the development of streamwise and spanwise vortices. The technique is effective in the range of angles of attack of 10 to 20 degrees, for which the uncontrolled flow is stalled.
- Attack and Fighter Aircraft
- Fluid Mechanics