Chaotic vibration characters of a graphite tube with an internal vapor-liquid-solid flow boiling

In this study, a fluidized bed graphite tube evaporator with an internal vapor-liquid-solid flow boiling in the tube was established and the signals of vibration acceleration of the tube were measured. The attractors of the fluctuations of flow induced vibration acceleration were investigated by applying the chaos theory, and the evolving mechanism of the chaotic attractors of vapor-liquid-solid flow induced vibration signals at varied solid holdup and steam pressure was analyzed. The results indicate that the multiphase flow induced vibration has a chaotic nature. The chaotic attractor of the vibration acceleration signals can display the multiphase flow vibration behavior. Higher fluid mixture density and turbulent vapor bubble number result in denser, bigger and more complex chaotic attractor. Fluidized solid particles have an obvious influence on the vibration behavior of the graphite tube with internal vapor-liquid flow boiling. (C) 2020 Elsevier B.V. All rights reserved.