Fractal-Dimension Crossovers in Turbulent Passive Scalar Signals
Fractal-Dimension Crossovers in Turbulent Passive Scalar Signals
复制标题
湍流无源标量信号中的分形维交叉
DOI：
--
复制
发表时间：
1993
期刊：
影响因子：
--
通讯作者：
D. Lohse
中科院分区：
文献类型：
--
作者：
S. Grossmann;D. Lohse
根据流体动力学方程计算湍流被动标量信号的分形维数δg(1)。 δg(1) 取决于尺度。对于较小的普朗特（或施密特）数 Pr 1 ，我们会得到第三个中间范围，其中信号极其褶皱并且 δg(1) = 2。在该范围内，无源标量结构函数 Dθ(r) 具有稳定状态。我们计算交叉的 Pr 依赖性。使用我们最近引入的简化波矢量集近似，可以在流体动力学方程的数值解中观察平台状态。
The fractal dimension δg(1) of turbulent passive scalar signals is calculated from the fluid dynamical equation. δg(1) depends on the scale. For small Prandtl (or Schmidt) number Pr 1 one gets a third, intermediate range in which the signal is extremely wrinkled and has δg(1) = 2. In that range the passive scalar structure function Dθ(r) has a plateau. We calculate the Pr-dependence of the crossovers. The plateau regime can be observed in a numerical solution of the fluid dynamical equation, employing a reduced wave vector set approximation introduced by us recently.