When liquids flow in the pipelines, the onset of cavitation can be characterized by a variant of the Euler number known as the cavitation number (CN), which is based on the velocity and denoted by C in this paper. Conventionally, cavitation is considered to be induced when C ~ 1. However, experimental observations and several pipe bursts indicate that the CN may incorrectly predict the onset of cavitation. For example, when leakage occurs in the pipeline or a valve in the pipeline is opened, the resultant pressure loss generates a dynamic pressure wave with a small amplitude, which may lead to bubble formation, even though C ~ 1 is not satisfied. Hence, this paper proposes another CN based on the amplitude of the generated dynamic pressure wave, rather than the velocity, for ascertaining the onset of cavitation. The validity of the proposed CN was verified through experiments and a case study. The results indicated that the proposed CN can be effectively used for cavitation prediction induced by pressure fluctuations and for investigating phenomena such as pressure fluctuation, leakage, and corrosion in liquid pipelines, tanks, and pressure vessels, as well as the safety design of liquefied natural gas tanks and tankers.

当液体在管道中流动时，气蚀的发生可以用欧拉数的一种变化来表征，即欧拉数（CN），该数基于速度，在本文中用C表示。传统上，空化被认为是当被诱导Ç  〜1。然而，实验观察和几个管突发指示CN可能会错误地预测气蚀的发生。例如，当管道中发生泄漏或打开管道中的阀门时，所产生的压力损失会产生振幅较小的动压力波，即使C 〜1不满意。因此，本文提出了一种基于生成的动态压力波的振幅而非速度的CN，以确定空化的开始。通过实验和案例研究验证了所提出的CN的有效性。结果表明，所提出的碳纳米管可以有效地用于压力波动引起的气蚀预测和液体管道，储罐和压力容器中压力波动，泄漏和腐蚀等现象的研究，以及液化天然气的安全设计。油箱和油轮。