论文标题
湍流的速度方向描述
Speed-direction description of turbulent flows
论文作者
论文摘要
在本说明中，我们引入了速度和方向变量，以描述不可压缩粘性流动的运动。流体速度$ {\ bf u} $被分解为$ {\ bf u} = u {\ bf r} $，带有$ u = | {\ bf u} | $ {\ bf u} | $ {\ bf r} = {\ bf r} = {\ bf u}/| {\ bf u} | $。我们考虑将Navier-Stokes方程的定向分配为$ u $的方程组和$ {\ bf r} $。 $ u $的方程式特别简单，但仅维护系统的能量平衡。在发达的湍流中速度和方向波动之间存在较弱的相关性的假设，我们进一步说明了$ u $ - $ {\ bf r} $变量的应用，以描述剪切湍流的平均统计数据。标准（完整的）雷诺应力张量不会出现在平均流量轮廓的结果方程中。
In this note we introduce speed and direction variables to describe the motion of incompressible viscous flows. Fluid velocity ${\bf u}$ is decomposed into ${\bf u}=u{\bf r}$, with $u=|{\bf u}|$ and ${\bf r}={\bf u}/|{\bf u}|$. We consider a directional split of the Navier-Stokes equations into a coupled system of equations for $u$ and for ${\bf r}$. Equation for $u$ is particularly simple but solely maintains the energy balance of the system. Under the assumption of a weak correlation between fluctuations in speed and direction in a developed turbulent flow, we further illustrate the application of $u$-${\bf r}$ variables to describe mean statistics of a shear turbulence. The standard (full) Reynolds stress tensor does not appear in a resulting equation for the mean flow profile.
