Preferential turbulence enhancement in two-dimensional compressions
Preferential turbulence enhancement in two-dimensional compressions
复制标题
二维压缩中的优先湍流增强
DOI：
10.1103/physreve.102.053213
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发表时间：
2020
影响因子：
2.4
通讯作者：
Fisch, Nathaniel J.
中科院分区：
文献类型：
--
作者：
Davidovits, Seth;Fisch, Nathaniel J.
当最初各向同性的三维 (3D) 湍流沿二维压缩时，压缩直接向压缩方向上的流动分量提供能量，而非压缩方向上的流动分量仅通过流体动力学方程的非线性间接经历压缩的影响。在这里，我们使用数值模拟研究这种二维压缩。对于最初的各向同性湍流，我们发现非线性可能不足以维持各向同性，与压缩平行的能量分量将主导湍流能量，从而产生许多后果。其中包括比 3D 压缩中更强且更容易持续的湍流能量增长的可能性，以及即使在没有热损失的压缩中也可能增加湍流马赫数。
When initially isotropic three-dimensional (3D) turbulence is compressed along two dimensions, the compression supplies energy directly to the flow components in the compressed directions, while the flow component in the noncompressed direction experiences the effects of compression only indirectly through the nonlinearity of the hydrodynamic equations. Here we study such 2D compressions using numerical simulations. For initially isotropic turbulence, we find that the nonlinearity can be insufficient to maintain isotropy, with the energy components parallel to the compression coming to dominate the turbulent energy, with a number of consequences. Among these are the possibilities for stronger and more easily sustained growth of turbulent energy than in 3D compressions and for an increasing turbulent Mach number even in a compression without thermal losses.