Experimental Investigation of the Effects of Blowing on Bursting of Strake Vortices.

摘要

Laser light sheet flow visualization and laser Doppler Anememetry (LDA) have been utilized to study the effects of pneumatic jet blowing on the breakdown and coupling locations of the strake and wing vortices generated over a generic fighter aircraft model with 55 degree sweep cropped delta wing planform fitted with forebody strakes. Experiments were conducted at low speed (15 m/sec), corresponding to a chord Reynolds number of 270,000, over an angle of attack range of 20 to 36 degrees. Flow visualization has been used to determine jet blowing locations and nozzle configurations which have the maximum beneficial effects of delaying both vortex breakdown and coupling of the strake and wing vortices. Significant reductions were observed both in vortex coupling interaction and in strake vortex breakdown at a blowing coefficient referenced to the wing area of 0.016. The LDA data indicated increases in the mean axial velocity above the vortices and increased turbulent velocities due to jet blowing.