当前位置: X-MOL 学术Phys. Rev. Fluids › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Characteristics of shearing motions in incompressible isotropic turbulence
Physical Review Fluids ( IF 2.7 ) Pub Date : 
T. Watanabe, K. Tanaka, K. Nagata

Regions with shearing motions are investigated in isotropic turbulence with the triple decomposition, by which a velocity gradient tensor is decomposed into three components representing an irrotational straining motion, a rotating motion, and a shearing motion. A mean flow around the shearing motions shows that a thin shear layer is sustained by a biaxial strain, which is consistent with Burgers’ vortex layer. The thickness of each shear layer is well predicted by Burgers’ vortex layer. Comparison between genuine turbulence and a random velocity field confirms that the biaxial strain acting on the shear is a dynamical consequence from the Navier–Stokes equations rather than from a kinematic relation. Interplay between the shear and biaxial strain causes enstrophy production and strain self-amplification. For a wide range of Reynolds number, the shear is strong enough for the instability to cause a roll-up of the shear layer, where the perturbation grows much faster than large-scale turbulent motions.

中文翻译:

不可压缩各向同性湍流中的剪切运动特征

研究了在三向分解的各向同性湍流中具有剪切运动的区域,通过该区域,速度梯度张量被分解为三个分量,分别代表非旋转应变运动,旋转运动和剪切运动。剪切运动周围的平均流量表明,薄的剪切层受到双轴应变的维持,这与伯格斯的涡旋层一致。每个剪切层的厚度可以通过伯格斯的涡旋层很好地预测。真实湍流和随机速度场之间的比较证实,作用在剪切面上的双轴应变是来自Navier-Stokes方程的动力学结果,而不是运动学关系。剪切应变和双轴应变之间的相互作用会导致回旋产生和应变自增。对于广泛的雷诺数,
更新日期:2020-06-17
down
wechat
bug