报告题目: VIVs of flexible structures in 2D uniform flow
报告人: Ekaterina Pavlovskaia, University of Aberdeen，教授，博导
报告时间: 18:10-19:00, 28th August 2020.
报告地点: 889 9240 5158 (Zoom ID)
Abstract:
Growth of subsea production systems for oil and gas extraction in deep water locations leads to building marine risers and pipelines of increased length. These long and thin structures constantly interact with surrounding water flow in various conditions. Vortices formed in the boundary fluid layer and resulting pressure oscillation cause prolong vibrations of the structure which can lead to a failure or accelerated fatigue. Accurate prediction of vortex induced vibrations (VIVs) can help to produce more robust structural design and lead to substantial savings in the offshore applications. Although the problem of vortex-induced vibrations could be addressed by different approaches, which include experimental studies, computational fluid dynamics modelling and analytical models, in present work, we focus on analytical model known as wake oscillator model.
In this work the fluid–structure interactions are considered by investigating a straight but slender pipe vibrating in a uniform water flow. The pipe is modelled as an Euler–Bernoulli beam with flexural stiffness. The external fluid force applied to the structure is the result of the action of sectional vortex-induced drag and lift forces which are modelled using nonlinear oscillator equations where various damping types including Van der Pol and Rayleigh were investigated. The coupled system of nonlinear partial differential equations describing the dynamic behaviour of the system was simplified employing Galerkin–type discretisation to obtain the reduced order model. The resulting ordinary differential equations were solved numerically providing multi-mode approximations of the structure displacement and non-dimensional fluid force coefficients. The proposed models were calibrated with the published experimental data by Sanaati and Kato (2012) and the prediction results were compared. The ongoing study aims to investigate different types of nonlinear damping in fluid oscillators and their role in accuracy of VIV prediction.
简介:
Professor Ekaterina Pavlovskaia, School of Engineering, the University of Aberdeen.
Professor Pavlovskaia works in the Centre for Applied Dynamics Research in the University of Aberdeen (http://www.abdn.ac.uk/engineering/people/profiles/e.pavlovskaia). She is a Chartered Engineer and Fellow of the Institution of Mechanical Engineers (FIMechE). She has graduated with first class degree with distinction in Mechanical Engineering from St.Petersburg State Polytechnical University in 1996 and obtained a PhD in Applied Mathematics and Physics from the Russian Academy of Science in 1998. Her expertise is in mathematical modelling and the applications she has been working on include novel resonance enhanced drilling technology, rotordynamics (turbines and engines), and riser mechanics. Ekaterina is an author of more than 150 scientific publications including 60+ refereed journal papers. She is founding director of a successful MSc in Subsea Engineering in the University of Aberdeen which was established in 2008.
