Session: 08-01-01 Risers, Pipelines & VIV

Paper Number: 104301

104301 - Fluid-Structure Interaction Vibration of Flexible Riser Transporting High-Speed Spiral Flow in Deep-Sea Mining 

Abstract: According to Hamilton’s principle and conservation law of mass and momentum, governing equations of fluid-structure interaction and structural dynamics of a flexible riser transporting high-speed spiral flow are developed for vortex-induced vibration (VIV) analysis for lifting pipe system in deep-sea mining. The bi-directional fluid-solid interaction between flexible riser and internal and external flows is achieved by data mapping and exchange among the flow field domain and the solid domain. The classic van der Pol oscillator is used to simulate the dynamic characteristics of VIV. The governing equations are then discretized and solved by the finite element method and the Runge-Kuta method. Based on the computational fluid dynamics (CFD) method, a three-dimensional flexible riser fluid-structure coupling numerical model is established, and the numerical accuracy of the model is verified by comparison with experimental results. Furthermore, dynamic characteristics of VIV of the flexible riser transporting spiral flow are investigated and the effects of flow velocity and density of the spiral flow on VIV responses are evaluated. The results show that the variation of the intrinsic frequency and the modal shapes of the flexible riser under the combined excitation of internal and external flows is evident, and the flow velocity and density of internal flow have significant nonlinear effects on the dominant frequency and vibration displacement of the flexible riser.

Keywords: Spiral flow; fluid-structure interaction; vortex-induced vibration (VIV); flexible riser; deep-sea mining.

Presenting Author: Cong Shen Tianjin university

Presenting Author Biography: Pursuing a Ph.D. in Naval architecture and ocean engineering at Tianjin University, Tianjin, China.
The present research topic concerns the CFD simulation of floating offshore structural loads.

EDUCATION
(1) SEPT 2019 – NOW, DOCTOR OF ENGINEERING, Tianjin University, Tianjin, CHINA.
(2) SEPT 2016 – NOV 2019, MASTER OF ENGINEERING, Dalian Maritime University, Dalian, China.
(3) SEPT 2012 – JULY 2016, BACHELOR OF ENGINEERING, Dalian Maritime University, Dalian, China.

Authors:

Jiayu Zhang Tianjin university
Nian-Zhong Chen Tianjin university
Cong Shen Tianjin university