Delta-wing leading-edge vortex subjected to jet blowing

Experiments were made to study the characteristics of leading edge vortex flow of a 50°-sweep delta wing, subjected to jets blowing on the leeward surface symmetrically with respect to the root chord, at X/c=0.7 and Y/s=±0.5, where Y/s=0 is located at the root chord, at X/c=0.7 velocity measurements were carried out in a half-span region of the delta wing at angles of attack α =10° and 25°. As found, at α=10° and 25° with C_μ=0.26, the leading-edge vortex developed on the leeside of the delta wing reveals the characteristic of similarity along the core which persists of the most downstream location measured, X/c=0.8. Further, the data of the swirl angle which is defined as the ratio of the two-component velocities measured show that the axis of the vortex core is tilted 5° downward in reference to the freestream at α=10° and tilted 10° at α=25°. Also found is that the swirl angle associated with the separated flow immediately above the leading edge of the delta wing is well correlated with the development of vortical flow along the chordwise direction.