The role of downstream ramps on penetration and mixing enhancement for supersonic injection flows
1997, American Institute of Aeronautics and Astronautics, Inc. An experimental study was conducted to investigate penetration and mixing enhancement of a discrete lowangled (25) supersonic (M=1.9) injection into a supersonic (M=2.9) cross flow. The enhancement was achieved by injecting the low-angled jet parallel to a compression ramp. Seven compression ramp configurations were studied. The jet-ramp interaction enhancement mechanisms included baroclinic torque vorticity, ramp spillage vorticity, bulk compression and the Magnus force. Shadowgraph photography was used to identify shock structures. Measurements of mean flow properties quantified the flowfield total pressure losses. Mie scattering images were used to qualitatively assess the flowfield and to quantify the plume size, trajectory and concentration decay rate. The results indicated that up to a 22% increase in penetration, a 39% plume expansion (~ mixing efficiency), and a 27% increase in the concentration decay rate, with a corresponding 17% increase in total pressure loss, can be achieved by injection over a compression ramp as compared to low-angled injection alone.