DIRECT NUMERICAL-SIMULATION OF TRANSITION TO TURBULENCE FROM A HIGH-SYMMETRY INITIAL CONDITION
DIRECT NUMERICAL-SIMULATION OF TRANSITION TO TURBULENCE FROM A HIGH-SYMMETRY INITIAL CONDITION
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DOI：
10.1063/1.868166
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发表时间：
1994-08-01
影响因子：
4.6
通讯作者：
PELZ, RB
中科院分区：
文献类型：
--
作者：
BORATAV, ON;PELZ, RB
高对称性初始条件的三维时间演化[J. Phys. Soc. Jpn. 54，2132（1985）]中的方法进行了数值模拟，其中Re = 1/nu = 500，1000，2000和5000，有效分辨率为1024（3）个配置点（171（3）个独立模态，最大波数k（max）= 340）。结果表明，在涡度拟能达到峰值之前，有一个很短的时间间隔，当本地量急剧增加。还发现，在此期间，6个涡偶极子（在原点）和3个偶极子（在π/2角）崩溃的两个独立的涡零点在相对的角落的域在一个几乎自相似的方式。随后相干涡旋破裂，随后局部量急剧减少。奇异性分析表明，在分辨率范围内，最大涡度尺度近似为（T-T（c））-1，即在破裂前不久。然而，峰值涡度的增加在某个时间停止，可能是由于粘性耗散效应。解析性条带宽度的时间演变表明，δ以比指数更快的速率接近零，但达到最小值并开始增加。这表明解仍然是一致解析的，就像粘性Burgers方程一样。
The three-dimensional (3-D) time evolution of a high-symmetry initial condition [J. Phys. Soc. Jpn. 54, 2132 (1985)] is simulated using a Fourier pseudospectral method for Re = 1/nu = 500, 1000, 2000, and 5000 with an effective resolution of 1024(3) collocation points (171(3) independent modes, maximum wave number k(max) = 340). It is found that much before the peak enstrophy is reached, there is a short interval when the local quantities increase sharply. It is also found that during this interval, six vortex dipoles (at the origin) and three dipoles (at the pi/2 comer) collapse toward two separate vorticity null points at the opposite corners of the domain in a nearly self-similar fashion. The coherent vortices break up afterward, followed by a sharp decrease in local quantities. The singularity analysis shows that, within the limits of the resolution, the maximum vorticity scales approximately as (T-T(c))-1, shortly before the breakup. However, the increase in peak vorticity stops at a certain time, possibly due to viscous dissipation effects. The temporal evolution of the width of the analyticity strip shows that delta approaches zero at a rate faster than exponential, but reaches a minimum value and starts to increase. This suggests that the solution remains uniformly analytic, as is the case in the viscous Burgers equation.