Numerical Study of Shock Wave Impacting on the Double-Mode Interface in Nonuniform Flows
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摘要: 利用可压缩多介质黏性流动和湍流大涡模拟的二维计算程序MVFT-2D,针对初始非均匀流场密度为高斯分布、马赫数Ma=1.27激波作用下的双模态界面失稳现象,进行了数值模拟研究。数值模拟结果表明,处于非均匀流场中的双模态振幅耦合效应较弱,而且低密度区的初始大振幅界面扰动增长最快,高密度区的初始小振幅界面扰动增长最慢。通过进一步分析可知,在一定初始振幅范围内,非均匀流场低密度区的振幅增长率较高,混合区域更宽,湍动能较大,受初始振幅影响较大,导致该区域界面不稳定演化较快。其变化规律与均匀流场呈现相反趋势,说明非均匀流场界面不稳定性的发展规律与均匀流场存在较大差异。
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关键词:
- 密度非均匀流场 /
- Richtmyer-Meshkov不稳定性 /
- 初始扰动 /
- 数值模拟
Abstract: The double-mode Richtmyer-Meshkov (RM) instability, when the incident shock (Ma=1.27) impacting on several groups of initial double-mode cosine interface formed by different amplitudes in initially nonuniform flows whose density is Gaussian distribution, was numerically investigated using the large-eddy simulation code MVFT (multi-viscous-flow and turbulence).The numerical results show that the coupling effects between different amplitudes in the nonuniform flows are weak and the evolution of the interface with a large initial amplitude in the low density nonuniform area grows fastest, while that with a small initial amplitude in the high density nonuniform area grows slowly.Further analyses reveal that within a certain initial amplitude range, the amplitude growth rate and energy in the low density zone of nonuniform flows is larger than those in the high density zone, thus the influence of the initial amplitude on the low density zone is more obvious, which eventually leads to a faster evolution process of the RM instability.Moreover, the changing phenomena of uniform flows are opposite to nonuniform flows.Thus, it can be concluded that the evolution mechanisms of the RM instability between the nonuniform and uniform flows are distinctive. -
表 1 气体参数
Table 1. Initial paramenters of air and SF6
Gas Density/(kg·m-3) γ η/(10-6 m2·s-1) Prl D/(cm2·s-1) Air 1.29 1.40 15.5 0.71 0.204 SF6 5.34 1.09 18.2 0.90 0.097 表 2 双模态界面的初始振幅
Table 2. Initial amplitudes of double-mode cosine interface
No. A01/mm A02/mm 1 5.0 7.5 2 7.5 5.0 3 2.5 7.5 4 7.5 2.5 5 7.5 7.5 6 7.5 10.0 7 10.0 7.5 -
[1] YANG J, KUBOTA T, ZUKOSKI E E.Applications of shock-induced mixing to supersonic combustion[J].AIAA Journal, 1993, 31(5):854-862. doi: 10.2514/3.11696 [2] ARNETT D.The role of mixing in astrophysics[J].Physics, 1999, 127(2):213-217. https://128.84.21.199/abs/astro-ph/9909031v1 [3] AMENDT P, COLVIN J D, TIPTON R E, et al.Indirect-drive noncryogenic double-shell ignition targets for the national ignition facility:design and analysis[J].Physics of Plasmas, 2002, 9(5):2221-2233. doi: 10.1063/1.1459451 [4] LINDL J, LANDEN O, EDWARDS J, et al.Review of the National Ignition Campaign 2009-2012[J].Physics of Plasmas, 2014, 21(2):020501. doi: 10.1063/1.4865400 [5] SMALYUK V A, CASEY D T, CLARK D S, et al.First measurements of hydrodynamic instability growth in indirectly driven implosions at ignition-relevant conditions on the National Ignition Facility[J].Physical Review Letters, 2014, 112(18):185003. doi: 10.1103/PhysRevLett.112.185003 [6] SMALYUK V A, TIPTON R E, PINO J E, et al.Measurements of an ablator-gas atomic mix in indirectly driven implosions at the National Ignition Facility[J].Physical Review Letters, 2014, 112(2):025002. doi: 10.1103/PhysRevLett.112.025002 [7] KUMAR S, VOROBIEFF P, ORLICZ G, et al.Complex flow morphologies in shock-accelerated gaseous flows[J].Physica D:Nonlinear Phenomena, 2007, 235(1):21-28. https://www.sciencedirect.com/science/article/pii/S016727890700262X [8] ORLICZ G C, BALAKUMAR B J, TOMKINS C D, et al.A Mach number study of the Richtmyer-Meshkov instability in a varicose, heavy-gas curtain[J].Physics of Fluids, 2009, 21(6):064102. doi: 10.1063/1.3147929 [9] ANDREWS M J. Workshop: research needs for material mixing at extremes[R]. Los Alamos National Laboratory, 2011. [10] 刘金宏, 谭多望, 柏劲松, 等.激波管实验研究非均匀流场RM不稳定性[J].实验力学, 2012, 27(2):160-164. http://d.wanfangdata.com.cn/Periodical_sylx201202005.aspxLIU J H, TAN D W, BAI J S, et al.Experimental study of Richtmyer-Meshkov instability in nonuniform flow by shock tube[J].Journal of Experimental Mechanics, 2012, 27(2):160-164. http://d.wanfangdata.com.cn/Periodical_sylx201202005.aspx [11] BAI J S, LIU J H, WANG T, et al.Investigation of the Richtmyer-Meshkov instability with double perturbation interface in nonuniform flows[J].Physical Review E, 2010, 81(5):056302. doi: 10.1103/PhysRevE.81.056302 [12] WANG T, BAI J S, LI P, et al.The numerical study of shock-induced hydrodynamic instability and mixing[J].Chinese Physics B, 2009, 18(3):1127-1135. doi: 10.1088/1674-1056/18/3/048 [13] XIAO J X, BAI J S, WANG T.Numerical study of initial perturbation effects on Richtmyer-Meshkov instability in nonuniform flows[J].Physical Review E, 2016, 94(1):013112. doi: 10.1103/PhysRevE.94.013112