摘要: A low-speed wind tunnel investigation was conducted to determine if a smallsecondary airfoil, or wave propeller, oscillating in a rotary plunging motion, could significantly affect the airflow over a lifting airfoil surface enough... 展开 A low-speed wind tunnel investigation was conducted to determine if a smallsecondary airfoil, or wave propeller, oscillating in a rotary plunging motion, could significantly affect the airflow over a lifting airfoil surface enough to delay the onset of call. The lifting airfoil shape was a NACA 66(215)216, chosen for it's chordwise pressure instrumentation. Testing consisted of measuring the pressure distribution of the NACA 66(215)-216 airfoil past the stall angle-of-attack, and then again in combination with the wave propeller. The wave propeller was located in two different positions; above the lifting airfoils trailing edge, and aft of the trailing edge. The propeller was operated in both clockwise and counter-clockwise directions. The propeller effectiveness was evaluated by comparing the pressure distributions and computed lift curve slopes with and without propeller operation. Reynolds number varied from 1.28 x 105 to 2.56 x 105. Mechanical limitations resulted in testing to only ten percent of the desired wave propeller speeds. Results indicated that the wave propeller acted to block the air flow over the lifting wing causing early unsteady Excitation, Katzmayr effect, high lift. 收起