有压输水管道中气泡起动临界流速研究进展

Research Progress of Critical Velocity of Bubble Initiation in Pressurized Water Pipelines

有压长输水管道系统在设计时,已经充分考虑到管道系统的排气问题,但在一些不利工况下,输水管道中会出现气泡,并在管线局部高点聚集形成气团,严重影响供水管线系统的正常运行。目前对有压输水管道中气泡起动临界流速的研究表明,气泡起动临界流速与管道内的水流流速、管道倾角等密切相关。但是不同研究结果得到的规律差异很大,相关机理尚不明晰,对于气泡体积等因素对气泡起动临界流速影响的研究成果较少,制约了输水工程进排气方案的合理设计,需对有压输水管道中气泡起动临界流速进行更加深入的研究。

In the design of the long-distance pressurized water pipeline system,the exhaust problem of the pipeline system has been fully considered.However,under some unfavourable working conditions,bubbles will appear in the water pipeline,and accumulate at local high points of the pipeline to form air masses,which seriously affect the normal operation of water supply pipeline system.The current research on the critical velocity of bubble initiation in pressurized water pipelines shows that the critical velocity of bubble initiation is closely related to the water flow velocity in the pipeline and the inclination angle of the pipeline.However,the rules obtained between different research results are very different,and the related mechanism is not clear.There are few research results on the influence of bubble volume and other factors on the critical flow velocity of bubble initiation,which restricts the reasonable design of the intake and exhaust plan of water delivery project.A more in-depth study of critical velocity of bubble initiation in pressurized water pipelines has to be done.