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为获得有压管道孔板局部阻力相邻影响系数的计算公式,采用标准κ-ε紊流模型模拟有压管道内设置单个以及结构参数相同的两个孔板时的管道流动,通过计算值与实测值的对比,选出最优网格划分方案和模型参数。对Re>137 870时有压管道中两孔板局部阻力相邻影响系数随孔板孔径比、厚径比及相对间距的变化关系进行了数值模拟试验,应用量纲分析法和数值分析法,推导出两孔板相邻影响系数计算公式,并采用相邻影响系数修正了局部水头损失计算公式,对修正后的公式进行检验。结果表明,当孔板相对间距LS/D<8时,修正后的公式计算值与实测值的最大相对误差为8.33%,而未修正的叠加计算值与实测值的最大相对误差达86.03%,当孔板相对间距LS/D≥8时,按照传统方法计算两孔板产生的总局部水头损失精度更高。
In order to obtain the formula for calculating the influence coefficient of the local resistance of the pressure pipe orifice adjacent to each other, the standard κ-ε turbulence model was used to simulate the flow of the pipe when there were two orifice plates with the same pressure and the same structural parameters. Comparison of measured values, select the optimal mesh scheme and model parameters. Numerical simulation experiments were carried out on the relationship between the adjacent coefficient of local resistance of two perforated plates in the pressure pipe when Re> 137 870 and the ratio of aperture, thickness to diameter ratio and relative spacing of the perforated pipe. Using dimensional analysis and numerical analysis, The formula for calculating the influence coefficient of adjacent two-hole plate is deduced, and the local influence coefficient is used to correct the local head loss formula, and the corrected formula is tested. The results show that the maximum relative error between the corrected formula and the measured value is 8.33% when the relative spacing of the orifice plate is less than 8, and the maximum relative error between the unmodified superposition and the measured value is 86.03% When the relative spacing of the orifice LS / D ≥ 8, according to the traditional method of calculation of the total local head two head orifice loss higher accuracy.