THE EFFECT OF CANARD LEADING-EDGE SWEEP AND DIHEDRAL ANGLE ON THE LONGITUDINAL AND LATERAL AERODYNAMIC CHARACTERISTICS OF A CLOSE-COUPLED CANARD-WING CONFIGURATION

摘要

A generalized wind-tunnel model, with canard and wing planforms typical of highly maneuver-able aircraft, was tested in the Langley high-speed 7- by 10-foot tunnel at a Mach number of 0.30. The test was conducted in order to determine the effects of canard sweep and canard dihedral on canard-wing interference at high angles of attack.nIn general, the effect of canard sweep on lift is small up to an angle of attack of 16°. How¬ever, for angles of attack greater than 16°, an increase in the canard sweep results in an increase in lift developed by the canard when the canard is above or in the wing chord plane. This increased lift results in a lift increase for the total configuration for the canard above the wing chord plane. For the canard in the wing chord plane, the increased canard lift is partially lost by increased interference on the wing.nFor the configurations with the canard in the wing chord plane, increasing the canard dihedral angle from -18.6° to 18.6° increased the maximum lift coefficient of the configuration. For the con¬figurations with the canard above the wing chord plane, the highest maximum lift coefficient was developed when the canard had no dihedral.nIn general, the configuration with the canards above the wing chord plane produced more linear pitching-moment curves throughout the angle-of-attack range than did the configuration with the canard in the wing chord plane. The theoretical data would seem to indicate that, when in the pres¬ence of each other, the canard and the wing generate vortex lift.