A stochastic analysis approach for marine riser’s cross-flow/in-line VIV under heave-induced parametric vibration

ABSTRACT

This study proposes a theoretical analysis model to analyse the marine riser's coupled cross-flow/in-line vortex induced vibration (VIV) under heave-induced time varying parametric vibration. Combining with the linear-wave theory, the stochastic phase spectrum method is used to simulate the stochastic multi-frequency parametric excitation in the time-domain to reproduce the real sea conditions. The nonlinearities are considered to capture the geometrical coupling of cross-flow/in-line displacements excited by hydrodynamic lift/drag forces and the wake-riser interaction. A generally good agreement between the proposed approach and other analyses can be observed. A parametric study is conducted, it is found that the drag coefficient is of significance for the riser's VIV, and the lift coefficient is affected by vortex shedding. The wave form, in terms of wave height and wave period, need to be considered with caution in design of a riser to avoid the occurrence of resonance under stochastic parametric excitation.

KEYWORDS:

• Marine riser
• cross-flow/in-line
• vortex induced vibration
• stochastic heave-induced parametric vibration
• real sea condition

Disclosure statement

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Additional information

Funding

This study had been supported by the National Natural Science Foundation of China [grant number 51808136], the Natural Science Foundation of Guangxi Province [grant number 2018JJB160058], the Guangxi Science and Technology Base and Talent Special Funds [grant number 2019AC20264], the Open Foundation of Guangdong Key Laboratory of Oceanic Civil Engineering [grant number LMCE202002], and the Open Foundation of Guangxi Key Laboratory of Disaster Prevention and Mitigation and Engineering Safety, China [grant number 2020ZDK002].