Experimental investigation on flow characteristics of a transverse jet with an upstream vortex generator

This paper aims at probing the flow characteristics of a jet in supersonic crossflow (JISC) by installing a vortex generator (VG) upstream of the jet orifice. Nanoparticle planar laser scattering (NPLS) and stereo-particle image velocimetry (SPIV) technologies were employed to observe the flowfield, and three cases were designed for comparison. CASE0 stands for JISC without passive VG. In CASE1 and CASE2, VG is installed at 20 mm and 80 mm upstream away from the jet orifice, respectively. Transient flow structures show that two flow modes exist when the VG wake interacts with the JISC. In CASE1, vortices are induced from both sides of the jet plume because of the VG wake. This leads to a complex streamwise vortex system. Penetration and lateral diffusion are enhanced. In CASE2, intermittent large-scale eddies in the VG wake cause large streamwise vortices at the windward side of the jet. The penetration depth is also enhanced while the lateral diffusion is restrained. In addition, experimental results show that the penetration depth is approximately 8.5% higher in CASE1 than that in CASE0, and the lateral diffusion is larger by about 17.0%. In CASE2, the penetration is increased by about 26.2%, while the lateral diffusion is enhanced by just 0.5%.