A minimal multiscale lagrangian map approach to synthesize non-Gaussian turbulent vector fields
A minimal multiscale lagrangian map approach to synthesize non-Gaussian turbulent vector fields
复制标题
合成非高斯湍流矢量场的最小多尺度拉格朗日图方法
DOI：
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发表时间：
2006
期刊：
影响因子：
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通讯作者：
C. Meneveau
中科院分区：
文献类型：
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作者：
C. Rosales;C. Meneveau
提出了一种简单的方法来生成合成矢量场作为湍流速度场的替代。该方法是基于最小拉格朗日映射，通过该映射，使用随机相位傅立叶模式产生的初始高斯场被变形。变形是通过移动流体粒子的低通滤波字段的序列在其固定的速度为一些尺度相关的时间间隔，插值到一个规则的网格，并施加无发散的条件。统计分析表明，由此产生的非高斯场显示了许多常见的湍流中观察到的属性，从歪斜和间歇性的速度梯度和增量概率分布，优先对齐的涡度与中间应变率，和非平凡的涡拉伸统计。只有当用与合成场中明显不存在的强涡流管相关的测量来询问数据时，差异才开始出现。为了探索动态含义，
A simple method is proposed to generate synthetic vector fields as surrogates for turbulent velocity fields. The method is based on the minimal Lagrangian map, by which an initial Gaussian field generated using random-phase Fourier modes is deformed. The deformation is achieved by moving fluid particles of a sequence of low-pass filtered fields at their fixed velocity for some scale-dependent time-interval, interpolating onto a regular grid, and imposing the divergence-free condition. Statistical analysis shows that the resultant non-Gaussian field displays many properties commonly observed in turbulence, ranging from skewed and intermittent velocity gradient and increment probability distributions, preferential alignment of vorticity with intermediate strain rate, and nontrivial vortex stretching statistics. Differences begin to appear only when interrogating the data with measures associated with intense vortex tubes that are conspicuously absent in the synthetic field. To explore the dynamical implicat...