Numerical Investigation of the Influence of Water Jumping on the Local Scour beneath a Pipeline under Steady Flow
Numerical Investigation of the Influence of Water Jumping on the Local Scour beneath a Pipeline under Steady Flow
复制标题
稳流条件下水跃对管下局部冲刷影响的数值研究
DOI：
10.3390/w9090642
复制
发表时间：
2017-08
期刊：
影响因子：
3.4
通讯作者：
Zhu Zhixia
中科院分区：
文献类型：
--
作者：
Fan Fei;Liang Bingchen;Li Yaru;Bai Yuchuan;Zhu Yanjun;Zhu Zhixia
在冲刷模拟中，通常采用刚盖近似代替自由面。本文研究了恒定流条件下刚性盖假设对冲刷坑预报精度的影响。首先，基于开源计算流体动力学（CFD）模型OpenFOAM，建立了考虑推移质和悬移质的局部冲刷模型。在本模型中，床面切应力的计算采用牛顿切应力公式，而不是传统的假设垂线流速服从对数分布的计算方法。采用流体体积法（VOF）捕捉自由表面，采用移动网格法跟踪床面变化。通过实验对模型进行了验证，模型结果与实测数据吻合较好。最后，研究了刚性盖假设对恒定流条件下冲刷面高程、床面切应力和冲刷坑形状的影响。结果表明，管道上方水面高程有所下降，且上下游水面高程差随无因次水深的减小而增大。与自由面条件相比，刚性盖近似计算的床面切应力和冲刷坑深度偏低。
Rigid-lid approximation is usually used to replace the free surface in scour simulation. The influence of the rigid lid assumption on the prediction precision of scour hole in steady flow is studied in this paper. Firstly, a local scour model was constructed based on the open sources Computational Fluid Dynamics (CFD) model OpenFOAM, where both the bed load and suspended load were considered. In the present model, the bed shear stress was calculated by the Newton shear stress formula, instead of the traditional calculation method with the assumption that the flow velocity in vertical direction complies with a logarithmic distribution. The Volume of Fluid (VOF) method was used to capture the free surface and a moving-mesh method was used to track the change of bed surface. Then, several experiments were chosen to validate the model, and the modeling results fitted well with the measured data. Lastly, the effect of the rigid lid assumption on surface elevation, bed shear stress and the profile of the scour hole in steady flow are studied. The result shows that the surface elevation suffers a drop above the pipeline, and the difference of surface elevation between the upstream and downstream increases with decreasing dimensionless depth. Compared with the free surface condition, the bed shear stress and scour hole depth computed with the rigid lid approximation were underestimated.
登录
查看更多内容
影响因子：
4.4
作者：
Mingde Zhao;Shailesh Vaidya;Qin Zhang;Liang Cheng;Liang Cheng
通讯作者：
Mingde Zhao;Shailesh Vaidya;Qin Zhang;Liang Cheng;Liang Cheng
DOI：
--
发表时间：
2010
期刊：
--
影响因子：
--
作者：
S. Patil;E. Valentine
通讯作者：
S. Patil;E. Valentine
影响因子：
3.6
作者：
M. Mattioli;A. Mancinelli;M. Brocchini
通讯作者：
M. Mattioli;A. Mancinelli;M. Brocchini
影响因子：
4.4
作者：
Ming Zhao;Liang Cheng
通讯作者：
Ming Zhao;Liang Cheng
DOI：
10.1061/(asce)0733-950x(2008)134:4(203
发表时间：
2008-07
期刊：
Journal of Waterway Port Coastal and Ocean Engineering-asce
影响因子：
--
作者：
Xiaofeng Liu;Marcelo H. García
通讯作者：
Xiaofeng Liu;Marcelo H. García