This paper presents a general theoretical reduced-order model capable of evaluating the multi-mode nonlinear dynamics of marine risers subject to uniform and sheared currents. The main objectives are to predict the vortex-induced vibration responses and parametrically compare between numerical and experimental results. The emphasis is placed on the analysis of cross-flow vibrations due to unsteady lift forces. The nonlinear equations governing riser axial/transversal motions are derived based on a top-tensioned beam model with typical pinned-pinned boundary conditions. The riser geometric nonlinearities owing to possible large dynamic displacements and multi-mode interactions are accounted for. To approximate the space-time varying lift force, the empirical hydrodynamic model, based on a nonlinear van der Pol wake oscillator with a distributed diffusive term, is used. A low-dimensional dynamic model and computationally-robust time-domain tool are then developed to evaluate the multi-mode fluid-riser interactions. These are very useful in dealing with large parametric studies involving varying system parameters.
|Number of pages||10|
|Publication status||Published - 2010|
|Event||The 29th International Conference on Ocean, Offshore and Arctic Engineering - Shanghai, China|
Duration: 6 Jun 2010 → 11 Jun 2010
|Conference||The 29th International Conference on Ocean, Offshore and Arctic Engineering|
|Period||6/06/10 → 11/06/10|
- numerical comparisons
- experimental comparisons
- vortex-induced vibrations
- marine risers
- uniform currents
- sheared currents
- marine engineering
Srinil, N., O'Brien, P., & Wiercigrocha, M. (2010). Numerical and experimental comparisons of vortex-induced vibrations of marine risers in uniform/sheared currents. 1-10. Paper presented at The 29th International Conference on Ocean, Offshore and Arctic Engineering, Shanghai, China, .