The diffusion of scalar and vector fields by homogeneous stationary turbulence
The diffusion of scalar and vector fields by homogeneous stationary turbulence
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均匀静止湍流引起的标量场和矢量场的扩散
DOI：
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发表时间：
1977
影响因子：
3.7
通讯作者：
E. Knobloch
中科院分区：
文献类型：
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作者：
E. Knobloch
本文给出了无源标量场和矢量场在湍流速度场作用下的扩散问题的精确欧拉公式。结果表明，在较短的自相关时间内，扩散方程对任何湍流都是精确的。对于非零自相关时间，找到了扩散方程的前几个修正项的形式，这些修正的结果是标量场、无发散场和无旋度场的扩散将是不同的。计算使用Kubo-Van Kampen-Terwiel技术，并进行了零普通扩散率和均匀，静止，各向同性，不可压缩，螺旋湍流。
An exact Eulerian formulation of the problem of diffusion of passive scalar and vector fields by a turbulent velocity field is obtained. It is shown that, in the short autocorrelation time limit, the diffusion equation is exact for any turbulence. For non-zero autocorrelation times the form of the first few correction terms to the diffusion equation is found. As a result of these corrections the diffusion of scalar, divergence-free and curl-free vector fields will be different. The calculations use the Kubo–Van Kampen–Terwiel technique and are carried out for zero ordinary diffusivity and for homogeneous, stationary, isotropic, incompressible, helical turbulence.