Static longitudinal and lateral-directional forces and moments were measured for elliptic- and crescent-wing models at high angles-of-attack in the NASA Langley 14 by 22-Ft Subsonic Tunnel. The forces and moments were obtained for an angle-of-attack range including stall and post-stall conditions at a Reynolds number based on the average wing chord of about 1.8 million. Flow-visualization photographs using a mixture of oil and titanium-dioxide were also taken for several incidence angles. The force and moment data and the flow-visualization results indicated that the crescent wing model with its highly swept tips produced much better high angle-of-attack aerodynamic characteristics than the elliptic model. Leading-edge separation-induced vortex flow over the highly swept tips of the crescent wing is thought to produce this improved behavior at high angles-of-attack. The unique planform design could result in safer and more efficient low-speed airplanes.
High Angle-of-Attack Aerodynamic Characteristics of Crescent and Elliptic Wings
1989
38 pages
Report
Keine Angabe
Englisch
Aerodynamics , Test Facilities & Equipment , Aerodynamic characteristics , Angle of attack , Swept wings , Wind tunnel tests , Wing planforms , Aerodynamic stalling , Lift , Pitching moments , Separated flow , Vortices , Directional stability , Flow distribution , Flow visualization , Lateral stability , Low speed stability , Rolling moments , Yawing moments