Vortex-induced vibrations of pipes conveying pulsating fluid

摘要: Abstract The vortex-induced vibrations of a long flexible pipe conveying fluctuating flows are investigated via two-mode discretization the governing differential equations. In present work, internal fluid velocity is assumed to have harmonically varying component superposed on steady mean velocity. Direct perturbation method multiple scales (MMS) adopted transform nonlinear partial equations (PDEs) into ordinary (ODEs), which then analyzed numerically for with principal parametric resonances during lock-in each first two modes. results indicate that in case containing flows, peak vibration amplitudes larger than flows. With increase detuning parameter frequency pulsating flow, variation range enlarges and narrows, jumping phenomenon amplitude changes from multi-value single-value returns between regions responses, has not been discovered yet. From amplitude-frequency response curves one can see hysteresis may occur small increments or decrements parameter. It also found if system condition certain mode, an obvious impact dynamics only when resonance occurs same mode. addition, numerical simulations (MNS) directly employed verify our implementation MMS.