Arbitrary Lagrangian-Eulerian Numerical Prediction for Local Scour Caused by Turbulent Flows
Arbitrary Lagrangian-Eulerian Numerical Prediction for Local Scour Caused by Turbulent Flows
复制标题
湍流局部冲刷的任意拉格朗日-欧拉数值预测
DOI：
10.1006/jcph.1996.0080
复制
发表时间：
1996
影响因子：
4.1
通讯作者：
S. Ushijima
中科院分区：
文献类型：
--
作者：
S. Ushijima
本文基于任意拉格朗日量，建立了一种数值预报沙床局部冲刷的方法。欧拉公式，其中三维贴体坐标适当产生的沙床剖面不稳定变形的流动。用三次样条插值法生成具有合理精度的曲线坐标。动量方程，湍流量，和沙浓度离散在拉格朗日计划，以保持二阶精度相对于时间和空间。对流的变量进行了评估与三阶精度，考虑到ALE制定所造成的网格点的速度。另一方面，沙床剖面预测与沙的连续性方程通过评估的总通量组成的床和悬沙所造成的牵引力和对流力的湍流。将该方法应用于三维局部冲刷试验结果。通过与实验结果的比较，验证了该方法对砂床剖面的预测效果是令人满意的，且与基于欧拉坐标系的预测结果相比有很大的改善。
A numerical prediction method has been developed for local scour on a sand bed due to turbulent flows on the basis of the arbitrary Lagrangian?Eulerian formulation, in which three-dimensional body-fitted coordinates are properly generated for the sand bed profile unsteadily deformed by the flows. The curvilinear coordinates are generated with reasonable accuracy by means of cubic spline interpolations. The equations for momentum, turbulent quantities, and sand concentration are discretized in a Lagrangian scheme so as to preserve second-order accuracy with respect to time and space. The convection of the variables are evaluated with third-order accuracy, taking account of the velocity of the grid point caused by ALE formulation. On the other hand, the sand bed profiles are predicted with the continuity equation for sand by evaluating the total flux consisting of the bed and suspended loads caused by the tractive and convective forces of the turbulent flows. This prediction method is applied to the results of a three-dimensional local scour experiment. From the comparison with the experimental results, it is verified that the sand bed profiles are satisfactorily predicted and that the predicted results are largely improved compared with those based on the Eulerian coordinate system.