Numerical investigation on passive supression of vortex-induced vibration using phenomenological models

• Grant number: 16/11080-3
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: September 01, 2016
• End date: August 31, 2017
• Field of knowledge: Engineering - Naval and Oceanic Engineering - Hydrodynamics of Ships and Ocean Systems
• Principal Investigator: Guilherme Rosa Franzini
• Grantee: Beatriz Sayuri Sato
• Host Institution: Escola Politécnica (EP). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Vortex-induced vibration phenomenon (VIV) is usually found in offshore engineering scenario and it may reduce the lifespan of structures such as risers due to structural fatigue.Several research efforts have been targeted for proposing solutions that decrease the oscillation amplitudes. Among these solutions, there is a class of passive supressors called NES (nonlinear energy sink). In the context of this work, a NES consists in rigid rod articulated to the axis of the cylinder subject to the VIV with a mass in the other extremity.The purpose of this research project is to carry out a numerical study of the influence that defines the supressor on the oscillation amplitude caused by VIV. In this work, the dynamics of the hidrolastic system will be represented by phenomenological models and the motion equations will be numerically integrated. Only rigid and elastically supported cylinders that can oscillates only in the cross-wise direction will be investigated..It is expected that, at the end of this project, curves and tables showing how the VIV oscillation amplitude is modified as functions of the supressor parameters and the reduced velocity.