AUTHOR=Luo Yangyang , Zhang Dapeng 

TITLE=Dynamic analysis of an axially moving underwater pipe conveying pulsating fluid

JOURNAL=Frontiers in Marine Science

VOLUME=Volume 9 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/marine-science/articles/10.3389/fmars.2022.982374

DOI=10.3389/fmars.2022.982374

ISSN=2296-7745

ABSTRACT=In this paper, both linear and non-linear dynamics of a slender and uniform pipe conveying pulsating fluid, which is axially moving in an incompressible fluid, are comprehensively studied. The vibration equations of the system are established, including coordinate conversion system, an "axial added mass coefficient" describing the additional inertia forces caused by the external fluid, Kelvin-Voigt visco-elastic damping and a kind of nonlinear additional axial tension. The vibration equations are discretized by the Galerkin procedure and solved by the Runge-Kutta approach, and the validity of the solution procedure is carefully checked. After that, the linear and non-linear responses of the system are studied when the internal flow velocity and the axially moving speed of the pipe are small. For linear responses, the Kelvin-Voigt visco-elastic damping has great influences on the second and the third modes of the system. For the nonlinear dynamic, the results are rich and changeful, including the first and the second principal parametric resonances, the secondary resonance, the combination resonance, periodic-1 motion, quasi-periodic motion and chaotic motion.