The characteristics of the trapezoidal weir flow are measured using a one-dimensional laser Doppler anemometer for two different flow conditions. The governing equations of the flow are solved using Standard k–ε, Realizable k–ε, Modified k–ω and Reynolds Stress Model based on the Reynolds-Averaged Navier–Stokes Equations and by Large Eddy and Detached Eddy Simulations. ANSYS-Fluent package program is used for the numerical analysis of flow with the same experimental conditions. The free surface of the trapezoidal weir flow is computed by the volume of fluid method. The effect of the selected grid structure on the numerical results is examined by Grid Convergence Index. Moreover, two-dimensional (2D) and three-dimensional (3D) analyses of the trapezoidal weir flow are included to estimate the effects of side walls. Experimental results of the velocity field and free surface profiles are compared to the numerical results of 2D and 3D simulations for the validation purposes. From the comparisons it is concluded that the Reynolds Stress Model estimates the flow field more accurately compared with those of the other models used in the present study. Furthermore, the flow characteristics such as turbulence kinetic energy, energy spectrum and pressure distributions for different flow rates are presented. Lastly, the discharge coefficients for different flow–weir configurations are compared experimentally and numerically.

使用一维激光多普勒风速计针对两种不同的流量条件测量梯形堰流的特性。流的控制方程使用标准解决ķ - ε，可实现ķ - ε，改性ķ - ω基于雷诺平均Navier-Stokes方程以及大涡流和分离涡流仿真的雷诺应力模型。ANSYS-Fluent软件包程序用于在相同实验条件下对流动进行数值分析。梯形堰流的自由表面是通过流体体积法计算的。通过网格收敛指数检查所选网格结构对数值结果的影响。此外，还包括梯形堰流的二维（2D）和三维（3D）分析，以估算侧壁的影响。为了进行验证，将速度场和自由表面轮廓的实验结果与2D和3D模拟的数值结果进行了比较。从比较中可以得出结论，与本研究中使用的其他模型相比，雷诺应力模型估计的流场更准确。此外，还给出了不同流速下的流动特性，例如湍流动能，能谱和压力分布。最后，通过实验和数值比较了不同流量型配置的排放系数。