针对河岸冲刷、河床演变显著的河流，建立考虑河岸变形的三维水沙数值模型，对黄河大柳树河段的河势演变进行数值模拟分析研究。模型中利用三角形网格和局部网格移动及局部加密技术，采用有限体积法离散控制方程，以及基于非结构化同位网格中的SIMPLE算法进行数值求解。依据2011年11月至2012年10月黄河大柳树河段典型断面实测资料对数值模拟结果进行验证，模拟结果与实测结果吻合较好。结果表明该模型能够较好地模拟黄河大柳树河段的水流运动和河床演变，模型中提出的河岸修正技术和局部网格加密技术可有效提高模拟计算精度和效率。%Aiming at the river where there is a severe bed scour and remarkable river chanml process caused by river⁃bank collapse, a three⁃dimensional (3D) numerical model for water flow and sediment is established under the conditions of considering the river⁃bank erosion. A finite volume method combined with the unstructured grids is applied to dispersion of a governing equation, and the SIMPLE algorithm with the unstructured collocation grids is used to deal with the coupled problems of the pressure and velocities. The numerical simulation results are verified with the measured data from November 2011 to October 2012, and the calculated results agree well with the measured data. The numerical simulated results demonstrate that the model can reasonably simulate the water flow and riverbed processes in the Daliushu reach of the Yellow River. The locally⁃adaptive grid technique and locally⁃encryption grid technique on the basis of the non⁃orthogonal grids given by the numerical model can effectively improve the calculation accuracy and efficiency in the numerical simulation.
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