R.A.E. high-speed wind-tunnel tests of the trailing-edge controls on a delta wing with 52-deg sweepback

Abstract

Tests have been made in the Royal Aircraft Establishment 10-ft x 7-ft High-Speed Wind Tunnel to determine the effectiveness of trailing-edge controls on a delta wing, of 52 deg leading-edge sweep and NACA 0010 section (trailing-edge angle 12 deg) using the half-model technique. Three plain controls were tested-an inboard control, an outboard control, and the two combined. For a trimmed CL of 0.2 to 0.3, there is no appreciable reduction of effectiveness on any control below M = 0.87. For M = 0.94, all controls have at least 50 per cent. of their low-speed effectiveness in pitch and roll. At higher incidence, reductions in effectiveness occur, particularly near M = 0.87, but are mostly associated with the effects of control deflection on tip stalling. The tests were made at R = 1.8 X 10power6 (based on mean chord) and hence the results may give a pessimistic idea of the behaviour at high Reynolds number. The pitching-moment characteristics show that cropping the pointed wing tip alleviates the tip stalling, as expected. For the cropped wing, the backward shift, with Mach number, of the aerodynamic centre at CL = 0.2 is less than 0.04c up to M = 0.93