The dynamic response of a pressurized, hot, flexible fluid-conveying marine pipeline

ABSTRACT

The transverse vibration of a pressurized, hot, flexible fluid-conveying pipe is investigated analytically via a coupled nonlinear partial differential equation where the effects of operating variables such as internal fluid temperature variation, mass ratio, pipe thickness, internal pressurization, Coriolis effect, axial acceleration of the internal fluid and cross-sectional area change, are fully captured. For this problem, a segment of a marine pipeline resting on the ocean floor is idealized as an elastic beam on an elastic foundation using the recently refined Euler-Bernoulli beam theory. Employing the hybrid Fourier-Laplace transforms, closed-form analytical expressions for the transverse natural frequencies are obtained in dimensionless form. In particular, two natural frequencies are noted to be associated with the phenomena as correctly identified in earlier results. Flow velocity was dependent on flow conditions and was found to increase with a decrease in the inlet operating temperature and thermal gradient. The operating pressure did not show any significant influence while the area deformation and pipe thickness increased. For the pipe thickness, the natural frequency was found to be similar irrespective of the thickness at the onset of the flow and decreased at a slower rate as it increased.

KEYWORDS:

• Thermal effect
• transverse vibrations
• fluid-conveying pipe
• natural frequency
• pipe thickness

Disclosure statement

No potential conflict of interest was reported by the author.

Additional information

Notes on contributors

Adekunle O. Adelaja

Adekunle O. Adelaja obtained his B.Sc., M.Sc., and PhD. in Mechanical Engineering from Obafemi Awolowo University, University of Ibadan and University of Lagos, Nigeria, in 1995, 1998 and 2012 respectively. He is a Senior Lecturer in the Department of Mechanical Engineering, University of Lagos, Nigeria where he has been since 2000. He was a Postdoctoral Fellow at the University of Pretoria (Thermofluid group), South Africa between 2012 and 2014 where he is worked on 2-phase flow in inclined tubes. His areas of research are Two-phase flow in inclined tubes, Heat transfer, and enhancement, thermo-mechanical behavior of offshore pipeline and Energy studies.