Two different arrangements of the weir (i.e., straight weir and rectangular labyrinth weir) were used to evaluate the effects of geometric parameters such as weir shape, weir spacing, presence of an orifice at the weir, and bed slope on the flow regime and the relationship between discharge and depth, variation and distribution of depth-averaged velocity, turbulence characteristics, and energy dissipation at the fishway. Computational fluid dynamics simulations were performed using FLOW-3D® software to examine the effects on flow conditions. The numerical model was validated by comparing the calculated surface profiles and velocities with experimentally measured values from the literature. The results of the numerical model and experimental data showed that the root-mean-square error and mean absolute percentage error for the surface profiles and normalized velocity profiles of plunging flows were 0.014 m and 3.11%, respectively, confirming the ability of the numerical model to predict the flow characteristics of the pool and weir. A plunging flow can occur at values of L/B = 1.83 (L: distance of the weir, B: width of the channel) and streaming flow at L/B = 0.61 for each model. The rectangular labyrinth weir model has larger dimensionless discharge values (Q+) than the conventional model. For the conventional weir and the rectangular labyrinth weir at submerged flow, Q is proportional to 1.56 and 1.47h, respectively (h: the water depth above the weir). The average depth velocity in the pool of a conventional weir is higher than that of a rectangular labyrinth weir. However, for a given discharge, bed slope, and weir spacing, the turbulent kinetic energy (TKE) and turbulence intensity (TI) values are higher for a rectangular labyrinth weir compared to conventional weir. The conventional weir has lower energy dissipation than the rectangular labyrinth weir. Lower TKE and TI values were observed at the top of the labyrinth weir, at the corner of the wall downstream of the weir, and between the side walls of the weir and the channel wall. As the distance between the weirs and the bottom slope increased, the average depth velocity, the average value of turbulent kinetic energy and the turbulence intensity increased, and the volumetric energy dissipation in the pool decreased. The presence of an opening in the weir increased the average depth velocity and TI values and decreased the range of highest TKE within the pool, resulted in larger resting areas for fish (lower TKE), and decreased the energy dissipation rates in both models.

使用两种不同的堰布置（即直堰和矩形迷宫堰）来评估几何参数（例如堰形状、堰间距、堰上孔口的存在以及床坡度）对流态和流态的影响。流量与深度的关系、深度平均速度的变化和分布、鱼道湍流特征和能量耗散。使用 FLOW-3D® 软件进行计算流体动力学模拟，以检查对流动条件的影响。通过将计算的表面轮廓和速度与文献中的实验测量值进行比较来验证数值模型。数值模型和实验数据结果表明，切入流表面剖面和归一化速度剖面的均方根误差和平均绝对百分比误差分别为0.014 m和3.11%，证实了数值模型的能力。预测水池和堰的流动特性。对于每个模型，在L / B  = 1.83（L：堰的距离，B：通道宽度）值时会出现骤降流，在L / B  = 0.61 时会出现流流。矩形迷宫堰模型比传统模型具有更大的无因次流量值（ Q +）。对于潜流下的常规堰和矩形迷宫堰，Q分别与 1.56 和 1.47 h成正比（h：堰上方的水深）。常规堰池内的平均深度速度高于矩形迷宫堰。然而，对于给定的流量、床坡度和堰间距，与传统堰相比，矩形迷宫堰的湍流动能 (TKE) 和湍流强度 (TI) 值更高。常规堰的能量耗散比矩形迷宫堰低。在迷宫堰顶部、堰下游墙角处以及堰侧壁和通道壁之间观察到较低的 TKE 和 TI 值。随着堰与底坡距离的增大，平均深度速度、湍流动能平均值和湍流强度增大，池内体积能量耗散减小。堰中开口的存在增加了平均深度速度和 TI 值，并减少了池内最高 TKE 的范围，导致鱼的休息区域更大（较低的 TKE），并降低了两个模型的能量耗散率。