Flowfield study of a close-coupled canard configuration

Abstract

Abstract : A nulling five-hole pressure probe was used to complete a flowfield survey behind a close-coupled canard and wing model set at 22 degrees angle of attack. The canard and wing were both low-aspect-ratio, highly-swept, delta planforms with rounded leading edges. The model was set at the condition of maximum lift enhancement of the canard/wing configuration over a corresponding wing-alone configuration, based on previous force measurements. For comparison, the pressure measurements were made with the canard on and with the canard off. From the pressure measurements, flowfield velocity-vector, velocity-streamline and total-pressure-coefficient contours were plotted. These plots showed the dramatic effect of the canard vortex on the wing flowfield. The location and interaction of the canard and wing leading-edge vortices were analyzed. Large- scale reattachment of previously reversed flow over the wing was noted, as well as the re-establishment and strengthening of the wing leading-edge vortex. Close-coupled canard, Vortex interaction, Post-stall, High angle of attack, Agility.