论文标题
分层剪切流中的政权转变：水平和倾斜导管之间的联系
Regime transitions in stratified shear flows: the link between horizontal and inclined ducts
论文作者
论文摘要
我们提出了在层状分层倾斜导管（SID）流中的二维速度和密度场的分析解决方案，在层次分层的倾斜导管（SID）流中，沿沿通道动量方程中的扩散占主导地位，但在密度传输方程中的惯性占主导地位。我们将这种近似值称为动量中的静液压/引力/粘性，并且由于管理方程中的领先余额而导致的密度（HGV-A）近似值。分析解对长管极限的两层配置中的层流有效。在这种情况下，非二维音量通量由Froude编号$ fr^* = re_g/（a \，k）$，带有$ re_g $的引力雷诺数，$ a $ a $ a $ a $ a $ a $ k $ k $ a $ k $ a a demetralictal参数取决于该导管和分析的倾斜度。 HGV-A近似中的分析解决方案通过实验室实验的结果进行了验证，并使我们能够对SID流的动力学和特性获得新的见解。最重要的是，$ fr^*$的恒定值描述了在水平和倾斜导管中，均匀湍流的流动状态之间的过渡：从层流流到界面波，再到间歇性的湍流和持续的湍流。
We present the analytical solution for the two-dimensional velocity and density fields within an approximation for laminar stratified inclined duct (SID) flows where diffusion dominates over inertia in the along-channel momentum equation but it is negligible in the density transport equation. We refer to this approximation as the hydrostatic/gravitational/viscous in momentum and advective in density (HGV-A) approximation due to the leading balances in the governing equations. The analytical solution is valid for laminar flows in a two-layer configuration in the limit of long ducts. Under such conditions, the non-dimensional volume flux is given by the Froude number $Fr^* =Re_g/(A\,K)$ with $Re_g$ the gravitational Reynolds number, $A$ the aspect ratio of the duct, and $K$ a geometrical parameter that depends on the tilt of the duct and is obtained from the analytical solution. The analytical solution in the HGV-A approximation is validated against results from laboratory experiments, and allows us to gain new insight into the dynamics and properties of SID flows. Most importantly, constant values of $Fr^*$ describe, in both horizontal and inclined ducts, the transitions between increasingly turbulent flow regimes: from laminar flow, to interfacial waves, to intermittent turbulence and sustained turbulence.
