Decay of two-dimensional homogeneous turbulence
Decay of two-dimensional homogeneous turbulence
复制标题
二维均匀湍流的衰变
DOI：
10.1017/s0022112074000280
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发表时间：
1974
影响因子：
3.7
通讯作者：
D. Fox
中科院分区：
文献类型：
--
作者：
J. Herring;S. Orszag;R. Kraichnan;D. Fox
通过数值模拟（以谱形式和网格点形式）和理论上使用直接相互作用近似和试验场模型，研究了二维、均匀、各向同性、不可压缩湍流的衰减。计算涵盖雷诺数50 ≤ RL ≤ 100的范围。谱方法与有限差分方法的比较表明，前者与一个给定的分辨率是相当的精度与后者的分辨率的两倍。在较大雷诺数的数值模拟表明，早期报道的模拟不能用于测试惯性范围的理论。然而，流场的大尺度特征似乎是显着的雷诺数无关。直接相互作用近似是在令人满意的协议与模拟的能量包含的范围内，但大大低估了涡度拟能转移在高波数。后者的失败被追溯到一个无法区分对流和小包裹的流体的内在扭曲。另一方面，试验场模型似乎与所有波数和所有研究雷诺数的模拟结果非常一致。
The decay of two-dimensional, homogeneous, isotropic, incompressible turbulence is investigated both by means of numerical simulation (in spectral as well as in grid-point form), and theoretically by use of the direct-interaction approximation and the test-field model. The calculations cover the range of Reynolds numbers 50 ≤ RL ≤ 100. Comparison of spectral methods with finite-difference methods shows that one of the former with a given resolution is equivalent in accuracy to one of the latter with twice the resolution. The numerical simulations at the larger Reynolds numbers suggest that earlier reported simulations cannot be used in testing inertial-range theories. However, the large-scale features of the flow field appear to be remarkably independent of Reynolds number. The direct-interaction approximation is in satisfactory agreement with simulations in the energy-containing range, but grossly underestimates enstrophy transfer at high wavenumbers. The latter failing is traced to an inability to distinguish between convection and intrinsic distortion of small parcels of fluid. The test-field model on the other hand appears to be in excellent agreement with simulations at all wavenumbers, and for all Reynolds numbers investigated.