Effects of strake planform change on vortex flow of a double-delta wing

This study examines the effects of a strake planform change on the vortex characteristics of double-delta wings through wing-surface pressure measurements and the off-surface flow visualization of the wing-leeward How region. Three different shapes of strakes (65/90 deg sweep cropped-delta, 79 deg sweep single-delta, and 72/84 deg sweep cropped-delta) were tested. The double-delta wing configuration with the 79 deg sweep single-delta shape strake produced a more concentrated vortex system at upstream locations and showed advanced coiling and downward movement of the strake and wing vortices compared with the other two configurations. However the concentrated vortex system for the double-delta wing configuration with the 79 deg sweep single-delta shape strake tended to diffuse and break down much faster than the other two configurations as the flow proceeded downstream. The test results reveal that strake modification can greatly alter the vortex flow pattern around a double-delta wing.