大口径喷嘴水射流特性研究
Study on the Characteristics of Water Jet from Large Bore Nozzles

大口径喷嘴常用于远距离冲洗，在高速铁路供电系统带电水冲洗过程中，要平衡冲洗距离长、水柱绝缘电阻小、用水量少三者之间的矛盾。对带电冲洗领域常用的二段形喷嘴进行了研究，提出了在喷嘴内部增加节流环的方式，在不改变喷嘴直径的情况下，可快速调整喷嘴的出口速度、打击力和水柱含水量。通过对喷嘴内外流场进行仿真分析，得到了不同半径的节流环在不同位置时的喷嘴射流特性及相关规律，并发现直径一定的喷嘴对应存在一个节流环半径的极限值，当超出这个极限值后喷嘴的射流特性有明显下降。通过对不同半径的节流环在不同位置时对喷嘴射流特性的影响及规律的研究，为自动化、智能化带电水冲洗过程中喷嘴的优化选型提供了参考。
Large bore nozzles are commonly used for long-distance flushing. In the process of live water flush-ing in high-speed railway power supply systems, it is necessary to balance the contradiction be-tween long flushing distance, low water column insulation resistance, and low water consumption. A study was conducted on the commonly used two-stage nozzle in the field of electric flushing, and a method of adding a throttling ring inside the nozzle was proposed. Without changing the nozzle diameter, the outlet speed, striking force, and water column moisture content of the nozzle can be quickly adjusted. Through simulation analysis of the internal and external flow fields of the nozzle, the jet characteristics and related laws of the nozzle with different radii of the throttle ring at dif-ferent positions were obtained. It was found that a nozzle with a certain diameter corresponds to a limit value of the throttle ring radius. When this limit value is exceeded, the jet characteristics of the nozzle significantly decrease. By studying the influence and regularity of throttle rings with dif-ferent radii on nozzle jet characteristics at different positions, reference is provided for the optimi-zation and selection of nozzles in automated and intelligent charged water flushing processes.