横流中湍流射流的数值研究

为探索横流中湍流射流的穿透性和流场基本特征，分别采用大涡模拟和标准k-e 湍流模型计算了射流速度比率为10的横流中圆管湍流射流，对射流速度为50 m/s的雷诺数为16600。大涡模拟获得的射流中心轨迹与试验数据基本一致，同时捕捉到了射流上游的开尔芬-亥姆霍兹不稳定性引起的剪切层涡卷、始于近场并主宰远场的逆向旋转涡对和垂直上升尾涡。计算表明，逆向旋转涡对并非严格关于射流中心平面对称，而是随时间左右摆动，与试验结论一致。标准k-e 湍流模型得到的逆向旋转涡对严格关于射流中心平面对称，同时不能获得射流上游的剪切层涡卷和垂直上升尾涡。

Numerical Study of Turbulent Jet in Cross-flow

In order to probe into the penetrability of a turbulent jet in cross-flow (JICF) as well as its characteristics of the flow field, large eddy simulation (LES) and standard k-εturbulence model were employed separately to simulate a round turbulent jet in cross-flow with the velocity ratio of 10, the Re based on the jet velocity 50 m/s is 16600.The LES results of the trajectory show a good agreement with experimental data. Simulation also captured the dominating vortex systems: Kelvin-Helmholtz instability induced shear layer vortical roller, Counter-rotating Vortex Pair (CVP), which initially begins in the near field and dominates the far field, and upright vortex in the wake. The asymmetry of CVP about the central plane of the jet was also observed which was the conclusion of experiment. In contrast, the results of standard k-εturbulence model show the CVP was exactly symmetrical about the central plane of the jet, the shear layer vortical roller and the upright vortex in the wake were not observed.