超临界雷诺数下桥墩紊流宽度的计算方法

摘要

桥墩紊流宽度的计算与水流雷诺数的范围关系较大,将影响到计算成果的合理性.结合山区河流超临界雷诺数条件,采用格子Boltzmann方法模拟桥墩三维紊流流场,并结合大涡模拟和运动边界处理方法,分析不同来流、河形等条件下的桥墩三维紊流宽度,由此建立了顺直河道和弯曲河道中圆型桥墩相对素流宽度与弗劳德数之间的耦合关系.该研究成果通过四川邓家坝大桥航宽验算,与经验法及祖小勇算法比较,发现该方法得出的桥墩紊流宽度略小、其数值趋于合理.%The range of Reynolds number has a great influence on the calculation of turbulent width around bridge pier,which will affect the rationality of the calculation results.For the mountain rivers,the Lattice Bohzmann Model(LBM) is used to simulate three dimensional turbulent flow field of bridge pier with supercritical Reynolds number.Combining with large eddy simulation and moving boundary treatment method,we analysed three dimensional turbulent width of bridge piers under different flow and river conditions.Based on the results,the coupling relationship between the circular piers the relative turbulent width and the Froude number in the straight channel and the curved channel is established.Through the waterway width checking of Sichuan Dengjiaba bridge,compared with the empirical method and Zu Xiaoyong algorithm,we find that the turbulence width is smaller and more reasonable.