等宽明渠交汇口平面二维水流数值模拟*

采用雷诺平均Navier-Stokes（RANS）方程组，其中动量方程的雷诺应力项用雷诺应力（RAM）模型求解，运用Fluent软件模拟了90°等宽明渠交汇口6种流量比的二维水流运动。通过将数值模拟的分离区尺寸与试验资料进行比较，发现用RAM模型模拟在小流量比流动精度较高，建议采用采用混合湍流模型：当流量比小于0.583取RAM模型计算值，否则取H-L模型计算，并绘制了分离区长度、宽度与流量比关系图。

Two-dimensional numerical water flow simulation at equal-width open-channel junction

In order to mumerically simulate 2D flow,under 6 kinds of flow ratios,at a sharp-edged,open-channel junction with 90°for channels of equal width,software Fluent with RSM turbulence model is introduced to solve the Navier-Stokes Equations.The comparison between numerical simulation sizes of separation zones and experimental data prove that the RSM model does well in the flow of small flow ratio.Thus the hybrid turbulence model is recommended,and it is suggested to use the RSM model when the flow ratio is less than 0.583,otherwise,H-L model.Furthermore,the relation diagram of separation zones’ length,width and flow ratio is plotted.