内流对洪水冲击下管跨临界长度影响研究

为了研究洪水冲击管道时形成的管跨临界长度,分别介绍了洪水作用下管道的动力特性以及内流对管道特性的影响。针对管内流动与管外洪水冲击对于管道的作用,建立了内流、外流共同作用下的管道动力控制方程。结果表明:对于洪水冲击管道的问题,不应仅考虑洪水的作用,也应该考虑内流对于管道的作用;内流流速增大、压强增大、密度减小都将缩短临界长度。考虑内流的管跨临界长度,对设计及现场抢维修都具有借鉴作用。

Research on the Effect of the Internal Fluid on the Critical Span Impacted by Flood

This paper introduces the dynamic characteristics of the pipe impacted by a flood, as well as the effect on the pipe span within the internal fluid, in order to study the limited length of the span. Considering the impact from both the internal fluid and the flood, the equation of the internal and external fluids is established. Results indicate that it is essential to take internal flu- id parameters into account;the limited span will decrease with the increase of the velocity and the inner pressure of the internal fluid, but simultaneously increasing with the decrease of the density of the internal fluid. It is a guidance to calculating the limited span in time of design or urgent maintenance.