Propeller Slipstream Effects as Determined From Wing Pressure Distribution on a Large-Scale Six-Propeller VTOL Model at Static Thrust

During static-thrust tests of a large-scale general research model having a tilting wing and double-slotted flaps, static-pressure measurements were made on a wing segment behind one propeller to survey the effects of the slipstream. For the conditions of highest slipstream energy, the hovering end point of aerodynamic parameters for aircraft having vertical and short take-off and landing capability (V/STOL), the effect of the slipstream on the tilt-wing configuration (zero flap deflection) was a 60 spanwise variation in effective angle of attack in a span of slightly less than 1 propeller diameter • Effective changes in camber on the tilt-wing configuration as a result of slipstream rotation, the radial velocity gradient, and the resultant spanwise flow were negative and had a maximum magnitude of less than 2-percent chord. For the deflected-slipstream configuration (double-slotted flaps deflected), effects important to the hovering performance were found, including a 40-percent spanwise variation in effective thrust recovery and a 200 spanwise variation in effective thrust turning.