Development of predictive models of vortex-induced vibrations for the analysis of the dynamic behaviour of risers

• Grant number: 11/00131-2
• Support Opportunities: Regular Research Grants
• Start date: August 01, 2011
• End date: July 31, 2013
• Field of knowledge: Engineering - Mechanical Engineering - Transport Phenomena
• Principal Investigator: Bruno Souza Carmo
• Grantee: Bruno Souza Carmo
• Host Institution: Escola Politécnica (EP). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

The goal of this research project is to achieve a more complete understanding of the vortex-induced vibration (VIV) in risers and based on this new information, to put forward simplified models to predict the response of the structure and stabilish design criteria for the use of strakes, which are VIV supressors. The simulation of the flow in the fluid-structure interaction problems will be carried out using high-order methods. The same numerical technique will be employed to investigate the flow around risers with strakes and try to elucidate the details of the physical mechanisms that govern the functioning of these devices, and also to define the situations in which strakes are effective or not. Regarding the predictive models that will be proposed, two different approaches will be investigated. The first consists in developing models based on the simplified numerical solution of the physical problem. The simplification in this project will be of geometric type: first we will try to solve the flow in two-dimensional strips and next we will try to solve the flow in sparse three-dimensional segments. The second approach will be the development of a phenomenological model, based on the Ginzburg-Landau equation. The coefficients of this model will be obtained by means of nonlinear stability calculations of the flow. (AU)