Aerodynamic Characteristics of the Close-Coupled Canard as Applied to Low-to-Moderate Swept Wings. Volume 2. Subsonic Speed Regime.

摘要

An analysis of the effects of canard size, shape, position and deflection on the aerodynamic characteristics of two general research models having leading edge sweep angles of 25 and 50 degrees is presented. The analysis summarizes the findings of four experimental subsonic wind-tunnel programs conducted at the David W. Taylor Naval Ship Research and Development Center between 1970 and 1974. The analysis is based on four canard geometries varying in planform from a 60-degree delta to a 25-degree swept wing high aspect ratio canard. The canards were located at seven different positions and deflected from -10 to 25 degrees. Significant findings include: the excellent correlation between canard exposed area ratio and changes in lift, drag, and pitching moment; the deterimental effect of positive canard deflection; and the optimum longitudual position for each canard shape for maximum improvements in lift and drag. It is further concluded that the favorable aerodynamic changes caused by interference of the close-coupled canard are not significantly dependent on wing leading edge sweep or wing leading edge modifications. (Author)