An experimental and theoretical study of the behavior of a transverse
gas Jet injected behind a rearward-facing step in supersonic now is de
scribed. In-flight iodine planar laser-induced fluorescence imaging wa
s performed to study this flowfield at NASA Dryden Flight Research Cen
ter using a flight test fixture situated under the fuselage of an F-10
4G aircraft, Jet structure and penetration data were obtained, in addi
tion to limited characteristics for jet mixing and for supersonic flow
over a rearward-facing step in a flow regime and for injection locati
ons not extensively studied in the past. A model for jet behavior is d
escribed that places emphasis on the dynamics of the vortical structur
es observed to dominate jet cross section, The complex flowfield forme
d downstream of the step is represented by a combination of empirical
and analytical correlations, Model predictions for jet trajectories co
mpare reasonably well with results from the present in-flight experime
nts as well as with prior wind-tunnel experimental data.