Effects of Pressure Mismatch on Slot Injection in Supersonic Flow

Abstract

In inany applications of slot injection in supersonic or hypersonic flow, the static pressures of the external and injectant streams are not matched. We have developed a simplified analysis of cases with initial pressure mismatch for tangential slat injection into a hypersonic ( o r supersonic) external flow having a thick, turbulent initial boundary layer including tho effects of turbulentmiuing, viscid/inviscid'interaction, skin friction and heat transfer and heat release for reactive injectants. The treatment uses hypersonic (or supersoni.c) small disturbance theory, R power law shape for the initial boundary layer velocity profile and a Crscco integral to get the temperature profile, a turbulent entrainment model including the effect oE a Convective Mach Number, a quasi-1D assumption in the miring and burning region, an instantaneous, one-step heat release modo1 and simple models of skin friction and heat transfer. 'The initial adjustments at the slot lip and further interactions with the viscous regions by waves reflected off the lower wall are treated with weak, locally inviscid waves. Laminar cases can also he handled. Good agreement of predictions with experiment for several experimental cases for gross flayfield variables such as p(x), A ( r ) , M(x) , T,(x), ete. was achieved. Both overand underexpanded cases were treated. The calculations need only about 1-2 seconds of CPU time on an Amdahl 5890 c lass csmputer. Lastly, calculations for combustor flowfields for a generic Scramjet vehicle at a flight Mach number of 10 with 0 . 8 5 pj/p, 2 1.25 are @en and discussed . I