论文部分内容阅读
为分析某水电站月牙肋岔管群水力损失问题,按岔管分岔角设计并做了2组月牙肋岔管群水力模型试验,同时推导出一套适用于粗糙区边壁的n-Ks关系方程及数值模型验证方法,既可将常规管道损失计算中的n值换算成Ks值,进而求出岔管沿程水力损失值。数值模拟结果表明,随着分岔角的增大,岔管水力损失增大,且分岔处岔管断面不均匀系数增大;随着月牙肋板内伸长度的增加,水力损失呈先减小后增大的趋势,水力损失与肋板长度关系曲线中存在极值;不同的月牙肋板内伸长度,板后脱落涡运动模式不同。模型试验及数值模拟计算结果的比较表明,数值模拟法求得的水力损失值大多小于模型试验值,二者相对误差分叉1出口处偏大,分叉2出口处波动最大,分叉3出口处最小。
In order to analyze the hydraulic loss of crescent ribbed tube group of a hydropower station, two groups of crescent rib bifurcated tube group hydraulic model tests were designed and designed according to the bifurcation angle of the bifurcation tube. At the same time, a set of n-Ks relationship Equation and numerical model verification method can not only calculate the value of n in conventional pipeline loss calculation as Ks value, and then calculate the value of hydraulic loss along the branch pipe. Numerical simulation results show that with the increase of bifurcation angle, the hydraulic loss of bifurcation increases, and the nonuniformity coefficient of bifurcation bifurcation increases; with the increase of crescent rib internal elongation, the hydraulic loss decreases first There is an extreme value in the relationship between hydraulic loss and the length of the rib. Different crescent rib internal elongation and shedding vortex have different movement modes. The comparison between the model test and numerical simulation results shows that the hydraulic losses obtained by the numerical simulation method are mostly smaller than the model test values. The relative error branch 1 is larger at the exit point, the branch branch 2 has the largest fluctuation at the exit point, and the bifurcation 3 exit point Department at the smallest.