Vibrations of a vertical 90° pipe bend under two-phase flow conditions
International Journal of Structural Integrity
ISSN: 1757-9864
Article publication date: 19 July 2022
Issue publication date: 16 November 2022
Abstract
Purpose
A simulation framework that includes a finite element analysis (FEA) and computational fluid dynamics (CFD) model is generated to study the effect of unstable two-phase flow-induced vibrations at a vertical 90° pipe bend. The corresponding fluid-structure interaction (FSI) of an unstable flow may pose danger to the piping structure. This paper intends to discuss this interaction.
Design/methodology/approach
Four cases of flows under the slug flow and churn flow regimes were investigated. The flow regimes vary in superficial gas velocities with velocities from 0.978 m/s to 9.04 m/s, while the superficial liquid velocity is kept constant at 0.61 m/s. The pipe model consists of an internal diameter of 0.0525 m, a bend radius of 0.0762 m, and a stainless-steel pipe structure.
Findings
Results show that the average unstable void fractions increase with the superficial gas velocities, but the peak frequencies were constant at 13 Hz for three of the cases. The total displacement and von Mises stress increase with a declining rate in each subsequent case, while the RMS of von Mises stress begins to stall at superficial gas velocities between 5 m/s and 9.04 m/s. The peak frequencies of von Mises stress decrease in each subsequent case.
Originality/value
The proposed model can be used to investigate the FSI effect of unstable void fractions at pipe bends and could assist in the development of piping systems in which the use of piping elements arranged close together are unavoidable.
Keywords
Acknowledgements
The authors would like to acknowledge support from grant FRGS/1/2018/TK03/UKM/02/5 funded by the Ministry of Higher Education, Malaysia.
Citation
Shah Reza, S.D. and Rasani, M.R. (2022), "Vibrations of a vertical 90° pipe bend under two-phase flow conditions", International Journal of Structural Integrity, Vol. 13 No. 6, pp. 885-906. https://doi.org/10.1108/IJSI-03-2022-0028
Publisher
:Emerald Publishing Limited
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