Langley Full-Scale-Tunnel Investigation of the Maximum-Lift and Stalling Characteristics of a Trapezoidal Wing of Aspect Ratio 4 with Circular-Arc Airfoil Sections
Abstract
The results of an investigation at high Reynolds numbers and low Mach numbers to determine the maximum-lift and stalling characteristics of an aspect-ratio-4 trapezoidal wing with 10-percent-thick, circular-arc airfoil sections are presented in this paper. The tests included measurements of the lift, the drag, and the pitching-moment coefficients of the basic wing and of the wing with 0.20-chord droop-nose and rear flaps deflected both alone and in combination with one another. Scale effects were investigated at Reynolds numbers ranging from 3.27 x 10(exp 6) to 7.67 x 10(exp 6). In addition to the force measurements, the stalling characteristics of the wing were determined by means of tuft observations. The maximum lift coefficient of the basic wing is 0.63, and a value of 1.39 was obtained for the wing with the best combination of deflections of the droop-nose flaps and the full-span rear flaps. A droop-nose-flap deflection of 20 deg appears optimum for maximum lift with rear flaps both neutral and deflected 60 deg. The drag of the wing is high throughout the moderate and high angle-of-attack range. Deflecting the droop-nose flaps is effective in causing an appreciable reduction in the drag throughout the moderate and high angle-of-attack range. In general, the pitching-moment characteristics of the basic wing and of the wing with all combinations of flap deflection indicate a forward location of the center of pressure with respect to the quarter chord up to about 0.80 of maximum lift. With further increases in lift coefficient, the center of pressure of the basic wing and of the wing with flaps deflected individually moves rearward and large amounts of longitudinal stability are indicated through the stall. For the wing with the flaps deflected in combination with one another, marginal stability is indicated at the stall.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 1952
- Accession Number
- ADA376973
Entities
People
- Roy H. Lange
Organizations
- National Aeronautics and Space Administration