Study on mixing induced by Richtmyer-Meshkov instability by using buoyancy-drag model
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摘要: 采用浮阻力模型对激波管低压缩和激光加载高压缩情况下的Richtmyer-Meshkov不稳定性诱导混合现象进行了研究。通过与实验和理论分析结果进行比较发现:为了达到好的吻合, Richtmyer-Meshkov不稳定性情况下阻力系数的取值范围(2.0~5.36)比Rayleigh-Taylor不稳定性情况下的值(3.3~4.0)宽得多; 而在Richtmyer-Meshkov不稳定性情况下, 高压缩时阻力系数的不确定度(约为3.36)明显高于低压缩时的值(约为1.46), 模型的进一步完善还有待于更精确实验的验证。研究显示:指数律经验公式中指数随工况的不同而显著变化, 目前工程设计中采用指数律经验公式是粗糙的。
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关键词:
- 流体力学 /
- Richtmyer-Meshkov不稳定性 /
- 浮阻力模型 /
- 扰动界面 /
- 压缩比
Abstract: The mixing induced by Richtmyer-Meshkov instability under lower and high compression ratios is studied by using buoyancy-drag model.It is found by the comparison between the experimental and theoretical analytic results that in order to achieve good agreement, the range of the drag coefficient value chosen in Richtmyer-Meshkov instability is much wider than that in Rayleigh-Taylor instability; while in Richtmyer-Meshkov instability the uncertainty of the drag coefficient under high compression is larger than that under lower compression.It is pointed that the further improvement of the model needs to be validated by more accurate experiment.Moreover the study reveals that the exponent in empirical expression varies with calculation conditions remarkably and the use of the empirical expression in current engineering design is rough. -
表 1 实验中采用的流体和脉冲加速度性质参数
Table 1. Fluid combinations and characteristics for impusive accerleration experiments
No. 流体1 流体2 ρ1/(g·cm-3) ρ2/(g·cm-3) R A We Re 1 H2O CCl2F2 1.000 1.57 1.57 0.22 4 000 2 600 2 SF6 C4H10 0.067 0.81 12.10 0.85 1 100 8 000 3 SF6 CCl2F2 0.067 1.57 23.40 0.92 11 000 23 000 4 SF6 CCl2F2 0.032 1.57 49.10 0.96 6 000 25 000 -
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