90°多弯管阻力系数计算方法

为准确获得90°组合多弯管阻力系数,采用数值模拟方法对S弯管管内流动进行模拟,并通过分析归纳S弯管局部阻力的相邻影响机制及规律,提出了90°组合弯管阻力系数计算方法.研究结果表明:弯管阻力系数受2弯连接段长度影响的规律与文献试验结果一致,数值计算方法准确有效;当连接段长度大于4倍管径时,S弯管阻力系数呈线性增长;提出的90°组合弯管阻力系数计算方法考虑了多弯管间相邻影响,且采用提出的方法计算了3弯管和多弯管的阻力系数,并将结果与数值模拟结果进行了对比,二者之间的差距均在3％之内,适合工程应用.

Calculation Method of Resistance Coefficient in 90° Combined Bends

In order to gain accurate resistance coefficients, a calculation method of 90°combined bends was proposed by investigating on flow of S-like bends with numerical simulation method, analysing and summarizing local resistance adjacent impact mechanism and law. The results show that the numerical simulation method of bends is precise and efficient due to a good agreement between the impact on resistance coefficient by the length of 2 bends and experimental data of published papers. The local resistance coefficient of S-like bends increase linearly when the connection section is 4 times longer than bends' diameter. Considering adjacent impact of bends, the resistance coefficient on triple bends and multiple bends are calculated. The difference between the calculation method of 90°combined bends and numerical simulation , which is suitable for engineering use, is less than 3 percent.