Investigation of spoilers at a Mach number of 1.93 to determine the effects of height and chordwise location on the section aerodynamic characteristics of a two-dimensional wing

James N. Mueller
naca-tn-4180
Feb 1958


An investigation has been made at a Mach number of 1.93 to determine the effects of height and chordwise location on the section pressure distributions and section aerodynamic characteristics of a two-dimensional, 6-percent-thick, symmetrical wing. Spoilers with heights of 0.03, 0.05, and 0.07 chord were tested at chordwise locations of 0.41, 0.53, and 0.70 chord at a Reynolds number of approximately 1 x 10-to-the-sixth. An analysis of the data indicated that the spoiler with a height of 0.03 chord produced only small changes in the wing-section aerodynamic characteristics from those of the wing with no spoiler. The spoiler height of 0.05 chord appeared to be the optimum height, as compared with its increased effectiveness over that of the spoiler height of 0.03 chord and the large drag rise associated with the spoiler height of 0.07 chord. The most effective spoiler location was the most forward position (0.41 chord), where the spoiler influenced a flow region of reduced local Mach number. The most rearward spoiler, located at 0.07 chord, had the least center-of-pressure travel and the lowest drag rise with increasing spoiler height and angle of attack. The result of fixed transition near the leading edge was a slight increase in the effectiveness of the spoiler when the spoiler was located at the most rearward chordwise location. The experimental chordwise points of boundary-layer separation from the wing surface forward of and due to the presence of a spoiler were compared with previous separation data as correlated in NACA TN 3065. Good agreement was shown when the boundary layer was turbulent. The theoretical pressure distribution computed on the basis of the separation profile thus determined was in good agreement with the experimental results.

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