参数对输水管道水流冲击气团压力的影响

Influences of relevant parameters on pressure of current rush to air mass in pipeline system

从理论上研究了阀门前充水段长度、滞留气团的初始长度、多方指数n等参数对输水管道水流冲击气团最大压力的影响.研究表明,阀前充水段长度仅改变系统的波动频率而与冲击气团最大压力无关.在忽略水头损失时,滞留气团的初始长度与冲击气团最大压力无关,而在考虑水头损失时,滞留气团的初始长度越长,水流冲击气团的最大压力越小,衰减越快;随着多方指数n值增大,水流冲击气团的最大压力减少;管路中的初始稳定气压对水流冲击气团产生的最大压力影响显著.

A study was performed on the influences of some parameters, such as the length of water filling section before valves, initial length of detained air mass, polytropic exponent n, etc. on the maximum pressure of current rush to air mass. The result shows that the length of water filling section before valves is only related to the wave frequency of the system, and is irrelevant to the maximum pressure on air mass induced by current rush. When the water-head loss is neglected, the initial length of detained air mass is irrelevant to the maximum pressure on air mass, whereas, if the water-head loss is taken into account, the longer the initial length of detained air mass, the lower the maximum pressure on air mass, and the more rapid the decay of the maximum pressure. Besides, the maximum pressure on air mass decreases with the increase of the polytropic exponent n, and the initial stable air pressure in pipelines is of notable influences on the maximum pressure of current rush to air mass.