Vibration transients of reservoir-pipe-valve system caused by water hammer

Abstract

A severe oscillation, accompanied with an abnormal "click" sound, of a fuel feeding pipe system during valve closing, when the feeding flowrate reaches a certain value, is observed experimentally. A fluctuation model in which stiffness and damping coefficients of the vibration system are time varying is proposed. Each coefficient is composed of two parts, one of which is constant and the other is time varying. Based on this model, simulation transients of the vibration displacement, velocity and pressure in the pipe are presented. Simulations of the pressure transients are compared with experimental data detected by pressure transducer, which shows that both have fluctuations in the transient process at a large flowrate.

Effects of a water hammer and cavitation on vibration transients in a reservoir-pipe-valve system

“…The first consists of a fuel delivery pump (1), filter (2), throttle valve (3), safety valve (4), pressure transducer (5), switch valve (6) and a flowmeter (7). The second includes a part of the fuel transfer pipeline, a directional valve (8) which control the fuel flow to consumption unit (9) or to a low pressure reservoir. The pipeline, fixed on the base with irregular spaced supports, is made of aluminum alloy, and its length, diameter and thickness are 8.7 m, 30 mm and 3 mm, respectively.…”

“…Our test of the RPV system is designed for an aircraft fuel supply system. A detailed description of the experimental setup and parameters was given in (Miao et al, 2020), which can be referred to by interested readers. In the experiment, a computer executes the valve closing command automatically.…”

“…It is observed that when the feed flow rate reaches a certain value, the feed pipe system vibrates violently when the valve is closed, accompanied by an abnormal "click" sound. In the paper (Miao et al, 2020), we proposed a fluctuation model to simulate the vibration process of the system. The simulation successfully explained the occurrence of the violent random vibration and abnormal sound in the experiment.…”