Two-phase flow induced vibration of piping structure with flow restricting orifices

In this paper, two-phase flow-induced vibration in a horizontal piping structure with flow restricting orifices has been experimentally investigated. The effect of flow patterns, void fraction, mass quality and orifice area ratio on vibration response is evaluated in detail. The two-phase flow measurements and vibration signals were analyzed simultaneously in order to understand the effect of two-phase flow behaviour on the governing factors responsible for flow-induced vibration mechanisms. The results show that the dynamic vibration response of the structure increased with the increase in the liquid mass flux and upstream void fraction in the case of intermittent flow patterns. The flow pattern change across the orifice is found to strongly affect the magnitude of the resulting vibrations. The maximum response was found in the region where a transition to slug flow occurred. Also, the RMS amplitude of vibration increased with an increase in the gas flux for both stratified and annular flows. Flow pattern maps were therefore created for both horizontal and vertical dynamic responses. These maps can be used in evaluating the dynamic response of piping structures with flow restrictions which are commonly found in the power generation industry. This will allow for a better design and safe operation of systems suffering from multiphase flow-induced vibration. (C) 2019 Elsevier Ltd. All rights reserved.