Volume 4 Issue 1 ( March 2017 )

Pages 44-51

Steady-state Analysis of Supersonic Mixing Enhanced by a Three-dimensional Cavity Flow

Takayuki Oka, Taro Handa, Fujio Akagi, Sumio Yamaguchi, Toshiyuki Aoki, Koichiro Yamabe, Yusuke Kihara

[ABSTRACT ]

The supersonic mixing field induced by a novel wall-mounted cavity having a three-dimensional shape is investigated computationally. In the computation, the Reynolds-averaged Navier-Stokes (RANS) equations are solved to obtain the steady state solution. The resulting pattern of limiting streamlines is compared with the previous result of oil-flow surface visualization. The comparison shows that the pattern of limiting streamlines agrees well with the oil flow pattern not only inside the cavity but also around the injector. The computational jet-penetration heights are also compared with the experimental heights measured previously. The comparison shows that both heights agree well near the injector. Such agreements imply that the flows in the cavity and around the injector can be reproduced well by the present numerical simulation. The detailed flow structure is investigated using the computational results. It is found from the results that a vortex having a three-dimensional shape is produced in the cavity and that the shear-layer spanning the cavity deflects upward near the central plane of the duct owing to the upward flows induced by the vortex. It is also found that owing to the upward shear-layer deflection the jet discharged from the injector is protected from the primary flow having large momentum. As a result, the jet penetrates highly into the primary flow.

Keywords: Supersonic flow, Cavity flow, Mixing enhancement, Numerical simulation, Jet.

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