Experimental and nonlinear vortex lattice method results for variouswing-canard configurations

Abstract

Experimental measurements of the aerodynamic characteristics of five close-coupled wing-canard configurations up to moderately high angles of attack are used to evaluate the ability of the nonlinear vortex lattice method (NLVLM) to calculate the aerodynamic characteristics of such configurations. The longitudinal aerodynamic coefficients, the rolled-up vortex trajectories, and the pressure distributions are compared for the five wing-canard configurations, as well as for the three wing planforms for which experimental data is available. The investigation includes the effects of varying the canard deflections and the canard positions relative to the wing of the various configurations. The lift- and induced-drag coefficients which are evaluated by the NLVLM for the wing-canard configurations are found to be in good agreement with the experimental data up to the angle of attack of 20-25 deg. The NLVLM works even better for wings alone in that the pitching moment can also be well-predicted. Therefore, this tool can potentially be used in the by analysis process employed during the preliminary design for wing-canard configurations. Nomenclature AR = aspect ratio b - wing span, mm CD = induced-drag coefficient based on wing planform area CL = lift coefficient based on wing planform area Cm = pitching moment coefficient based on wing area and wing root chord Cp = pressure coefficient when Ap is the lifting