Pitch-Location Effects on Dynamic stall.
AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING
Pagination or Media Count:
Experimental investigations were conducted in the AFIT Smoke Tunnel to study the effects of pitch-location on dynamic stall. A NACA 0015 airfoil was rotated about four different locations at a constant angular rate and digital position and pressure information were recorded. This information was then converted into airfoil pressure distributions and integrated numerically to obtain airfoil force coefficients. Results of this investigation showed a direct relationship between the dynamic-stall angle of attack and the non-dimensionalized angular rotation rate, ND, defined as one-half the airfoil chord length times the angular rate divided by the freestream velocity. Based on the rotation points forward of the mid-chord, it was also shown that dynamic stall is delayed as the pitch location is moved aft from the leading edge. Experimental data was obtained for pitch locations of .08c, .25c, .50c and .61c and non-dimensional angular rates between .011 and .065. Keywords Stall, Dynamic stall, Increased lift, Ramp angle of attack, and Pitch location.
- Fluid Mechanics