组合弯管水流阻力特性及相邻影响数值模拟  

Numerical Simulation of Water Flow Resistance Characteristics and Adjacent Influences in Combined Elbows

作　　者：李江涛 石喜[1] 李露 LI Jiang-tao;SHI Xi;LI Lu(College of Civil Engineering,Lanzhou Jiaotong University,Lanzhou 730070,China)

机构地区：[1]兰州交通大学土木工程学院,甘肃兰州730070

出　　处：《水电能源科学》2022年第7期136-140,共5页Water Resources and Power

基　　金：国家自然科学基金项目(51969011);甘肃省自然科学基金项目(20JR10RA239)。

摘　　要：为探究有压输水管道中近距离组合弯管的水流阻力特性及相邻影响,采用标准κ-ε湍流模型进行了数值模拟,探讨了组合弯管的流场特性及局部阻力系数和相邻影响系数随雷诺数、相对间距和弯径比的变化规律。结果表明,不同相对间距时组合弯管中上游弯管的流场变化基本一致,而下游弯管中流场受上游弯管的影响,随着相对间距的增大,影响程度逐渐减小。局部阻力系数随雷诺数的增大而减小;随相对间距的增大呈先下降后又逐渐增大最后趋于平缓的趋势;随弯径比的增大而减小。相邻影响系数随雷诺数的增大而缓慢增大,整体受雷诺数的影响较小;相邻影响系数在相对间距为4左右时出现最小值,为0.68;随弯径比的变化亦出现最小值,根据研究结果在实际工程中选用弯径比为1~2之间的弯管较为合适。In order to explore the flow resistance characteristics and adjacent influences of the short-distance combined elbows in the pressurized water pipeline, a numerical simulation study was carried out using the standard κ-ε turbulence model. The flow field characteristics of combined elbows, as well as the variation of local drag coefficient and adjacent influence coefficient with Reynolds number, relative spacing and bending diameter ratio were discussed. The results show that the flow field of the upstream bend in the combined bend is basically the same when the relative spacing is different, while the flow field in the downstream bend is affected by the upstream bend. As the relative spacing increases, the degree of influence gradually decreases. The local drag coefficient decreases with the increase of the Reynolds number. With the increase of the relative distance, it first decreases, then gradually increases, and finally tends to be stable. It decreases with the increase of the bending diameter ratio. The adjacent influence coefficient increases slowly with the increase of the Reynolds number, and is less affected by the Reynolds number as a whole. The adjacent influence coefficient has a minimum value of 0.68 when the relative distance is about 4. The change has a minimum value. According to this result, it is more appropriate to choose a bend with a bend ratio between 1 and 2 in the actual project.

关 键 词：标准κ-ε湍流模型 组合弯管 阻力特性 相邻影响 

分 类 号：TV134.2[水利工程—水力学及河流动力学]