紊流随机理论在小浪底河段水流模拟中的应用

Stochastic turbulence theory for 3-D flows in the reach of the Xiaolangdi Project

针对黄河中游小浪底工程建成前的河段河流流动特点,提出了河流的三维水流数学模型。基于紊流随机理论,采用了各向异性紊流的R eyno lds应力数值格式和自由面位置的压力Po isson方程,并将精细壁函数应用于边壁处理。采用贴体座标,并利用交错网格系统和有限体积法离散湍流控制方程,采用S IM PLEC方法,计算了此河段的水面线、一些河道横断面上的流速沿河宽和沿垂线分布。计算结果都与原型实测成果基本吻合,从而证明了此模型可靠性。

A 3-D mathematical model was used to simulate the flow over the complex geometry of the Xiaolangdi Project. Stochastic turbulence theory was used to develop a numerical model of the Reynolds stresses for anisotropic turbulent flows that was solved with a pressure Poisson equation for the free surface flow. A refined wall function was used to treat the solid wall boundaries. Body-fitted coordinates and the finite volume method were used to discretize the turbulent equations together with a staggered grid system and the SIMPLEC algorithm. The model was used to simulate the surface level and velocity distributions at the various cross-sections in the reach. The results agree well with measured data in a physical model, which indicates that the model is reliable.