Eventos Anais de eventos
DINAME 2017
XVII International Symposium on Dynamic Problems of Mechanics
Stochastic analysis of vortex induced vibrations using a reduced model
Submission Author:
Gabriel Mario Guerra Bernadá , RJ , Brazil
Co-Authors:
Gabriel Mario Guerra Bernadá, Fernando Rochinha
Presenter: Gabriel Mario Guerra Bernadá
doi://10.26678/ABCM.DINAME2017.DIN17-0211
Abstract
Vortex-Induced vibrations plays an important role in many fields and is crucial in the design of offshore engineering systems and has received special attention lately due to its relevance for design of mooring and risers’ system as well to mono-column platforms for hydrocarbon exploration in deep waters. The use of phenomenological reduced models to analyses this kind of models, such as preliminary approach, is very useful tool to complement the results achieved via CFD (Computational Fluid Dynamics). The phenomenon plays an important role in many fields and is crucial in the design of offshore engineering systems, where the accurate prediction of structural instability is extremely important due that the vortex shedding behind bluff bodies may lead to degradation of structural performance or even structural failure. This work presents a stochastic analysis of this phenomena, taking into account uncertain input parameters in a phenomenological model taken into account results from Navier-Stokes equations model using a CFD solver as reference. This analysis can help to understand the behavior of the structure to critical situations and the effects of varying parameters in the response variables. The statistics moments are approximated by the nonintrusive sparse grid stochastic adaptive collocation method. This method has emerged in recent years as an attractive technique, due to that allows obtaining approximations of the interpolating function in the stochastic space. The method approximates the solution in the stochastic space using Lagrange polynomial interpolation, providing a simple way to approach the statistical moments of the system outputs. To improve the method when there are steep gradients or finite discontinuities in the stochastic space an adaptive technique was adopted to perform the analysis. Numerical simulations are performed to demonstrate the appropriateness of method applied for characterization of the statistical moments of the critical points as well as for the determination of the probability of occurrence of undesired phenomenon.
Keywords
Flow-induced Vibrations, uncertainty quantification, Adaptive Stochastic Collocation Method
