STUDY ON LATERAL JET INTERACTION WITH SUPERSONIC FREESTREAM

摘要

The purpose of this study is to study flow structures of lateral jet interaction with supersonic freestream over body of revolution and the associated effects on force amplification or/de-amplification with numerical simulation method. The finite-volume flow solver FLUENT is used to solve the Reynolds-averaged Navier-Stokes (RANS) equations with Shear-Stress Transport (SST) turbulence model. A comparison study between a circular spouting jet and a solid protruding cylinder indicates that a solid cylinder with limit height is not a proper description for jet interaction as it does not include plume under-expansion and proper vortex generation. Force decomposition combined with detail flow structure analysis show that upstream high pressure zone, downstream low pressure region, and wraparound effects are the main flow features that affect jet reaction force. In the downstream region, it appears that there are strong communications between vertical vorticity (ω_y) and transverse vorticity (ω_x), affecting downstream pressure level. If the strength of the transverse vorticity is stronger than the vertical vorticity, the jet interaction can induce much lower pressure at downstream of jet. If the vertical vorticity is stronger, downstream low pressure region tends to become smaller due to stronger air entrainment effect.