Numerical analysis on two-phase flow-induced vibrations at different flow regimes in a spiral tube

Spiral tubes are used in a wide range of applications and it is significant to understand the vibration introduced by two-phase flow in spiral tubes. In this paper, the numerical method is used to study the vibration induced by the gas-liquid two-phase flow in a spiral tube with different flow regimes. The pressure fluctuation characteristics at the pipe wall and the solid vibration response characteristics are obtained. The results show that the motion of small bubbles in bubbly flow leads to small pressure fluctuations with low-frequency broadband (0–50 Hz). The motion of the gas plug in the plug flow causes small amplitude periodic pressure fluctuation with a shortened low-frequency broadband (0–15 Hz) compared to the bubbly flow. The motion of the gas slug in the slug flow causes large periodic fluctuations in pressure with a significant dominant frequency (6–7 Hz). The wavy flow is very stable and has a distinct main frequency (1–2 Hz). The vibration regime in the bubbly flow and wave flow are close to the first-order mode, and the vertical vibrating component is dominant. The plug flow and slug flow excite higher-order vibration modes, and the lateral vibration component plays more important part in the vibration response.