Developing fluid flow in a curved duct of square cross-section and its fully developed dual solutions
Developing fluid flow in a curved duct of square cross-section and its fully developed dual solutions
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在方形横截面的弯曲管道中开发流体流动及其完全开发的双重解决方案
DOI：
10.1017/s0022112088000758
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发表时间：
1988
影响因子：
3.7
通讯作者：
W. Soh
中科院分区：
文献类型：
--
作者：
W. Soh
通过交错网格上的分解 ADI 有限差分法对方形截面弯曲管道中流体流动的发展进行了数值研究。在计算域内使用具有原始变量的中心差分方案来减少数值扩散。根据体积速度和水力直径，分别为 1/6.45 和 1/2.3 的曲率比选择两个雷诺数 574 和 790。发现二次流远比想象的复杂，至少出现了两对涡流。对于较高的曲率比，还观察到主流分离。此外，据观察，根据入口条件，下游的流动会发展成两种截然不同的状态。完全发展的纳维-斯托克斯方程的解在超出某个临界雷诺数时被证明不是唯一的。开发流似乎沿着一个特定的分支演变成完全开发的状态，完全开发的解决方案分为两部分。
Developing fluid flow in a curved duct of square cross-section is studied numerically by a factored ADI finite-difference method on a staggered grid. A central-difference scheme with primitive variables is used inside the computational domain to reduce numerical diffusion. Two Reynolds numbers, 574 and 790, based upon a bulk velocity and hydraulic diameter are chosen for curvature ratios of 1/6.45 and 1/2.3, respectively. It is found that the secondary flow is far more complicated than expected, with the appearance of at least two pairs of vortices. Main-flow separation is also observed for the higher curvature ratio. Furthermore, it is observed that the flow develops into two quite different states downstream, depending upon the inlet conditions. Solution of the fully developed Navier-Stokes equations is shown to be not unique beyond a certain critical Reynolds number. Developing flow seems to evolve into the fully developed state along a particular branch, into which the fully developed solution bifurcates.