Effects of wing sweep on lift-enhancement and flow patterns of close-coupled canard-configurations at high incidence

An experimental wind-tunnel investigation was undertaken to determine the characteristics of lift-enhancement and oil-flow patterns of close-coupled canard-configurations with different sweep delta-wings and delta-canards. The results of lift-measurement revealed the effect of wing sweep on lift-enhancement of close-coupled canard-configurations, and the flow visualization further interpreted the flow mechanism of lift-enhancement. It can be found that the lift-enhancement is substantially affected by the wing sweep and angles of attack. At certain angle of attack, the lower sweep wing has better effect of the lift enhancement than the higher ones. From oil-flow patterns, it can be found that the leading-edge vortex of low sweep delta-wing was prone to breakdown and the canard can promote flow patterns when the leading-edge vortex of delta-wing breakdown.