泄水建筑物下游冲刷坑二维数值模拟

发布时间：2018-04-14 19:58

本文选题：二维数学模型 + 局部冲刷坑　；参考：《泥沙研究》2017年03期

【摘要】：对巨亭水电站泄水建筑物下游局部冲刷过程进行了二维数值模拟。采用RNG k-ε湍流模型封闭N-S方程、有限体积法在计算网格上离散求解、VOF方法追踪自由水面;采用C语言编写用户自定义函数,以泥沙起动切应力作为床面泥沙起动判别标准,通过分析比较水流剪切力与泥沙起动切应力大小,用以控制冲刷坑底部边界变化;采用局部重构模型和弹簧光顺模型更新计算区域和网格质量,藉以模拟和追踪局部冲刷坑边界变化。研究表明,模拟结果与实测资料符合良好。在冲刷坑的冲刷过程中,床面剪切应力随着冲刷的进程急剧减小,湍动能随着冲刷的进程减小缓慢;床面剪切应力和湍动能沿程变化均较为剧烈,床面剪切应力沿程先增大后减小,床面湍动能则沿程减小。冲刷坑的纵向平衡形态或床面泥沙起动主要决定于床面剪切应力,床面湍动能对泥沙起动也具有重要影响。
[Abstract]:A two-dimensional numerical simulation of the local scour process downstream of the drainage structure of Juting Hydropower Station was carried out.The RNG k- 蔚 turbulence model is used to close the N-S equation, the finite volume method is used to discrete solve the free water surface on the computational grid, the user-defined function is written by C language, and the sediment initial shear stress is used as the criterion of sediment starting.The flow shear stress and sediment initial shear stress are analyzed and compared to control the bottom boundary change of the scour pit, and the local reconstruction model and spring fairing model are used to update the calculated area and mesh mass.To simulate and track the boundary changes of local scour pits.The results show that the simulation results are in good agreement with the measured data.In the scouring process of the scour pit, the shear stress on the bed surface decreases sharply with the scouring process, and the turbulent kinetic energy decreases slowly with the scouring process, and the shear stress and turbulent kinetic energy of the bed surface vary sharply along the course.The shear stress of the bed surface increases first and then decreases, while the turbulent kinetic energy decreases along the bed surface.The longitudinal equilibrium shape of the scour pit or the bed surface sediment starting are mainly determined by the bed surface shear stress, and the bed surface turbulent kinetic energy also has an important influence on the sediment starting.
【作者单位】：西北农林科技大学水利与建筑工程学院;
【基金】：国家自然科学基金项目(51279170)
【分类号】：TV147.5

【相似文献】