Modeling and simulation of vortex induced vibration on the subsea riser/pipeline (GRP pipe)

This paper presents the research work conducted to investigate the dynamics characteristics of the offshore riser pipeline due to vortex flow and to develop a model that could predict its vortex induced responses. Glass-fiber reinforced plastic (GRP) pipe is used for this study. A two-dimensional finite element computational method is implemented to approximately describe the dynamic behavior of the riser. The governing equation of motion was based on Hamilton´s principle, consists of the strain energy due to bending and axial deformation, kinetic energy due to both riser and internal fluid movement and also external force from currents and waves. A direct integration method namely Newmark integration scheme is proposed to solve the equation of motion. A MATLAB program code was developed to obtain the simulation results. The dynamic response of riser is shown in time domain and the numerical results are discussed. Several parameters effects are used to investigate the dynamic responses and the results show an agreement with the theory. As a conclusion, the mathematical model used has successfully shown the dynamic response of GRP pipeline and its dynamic characteristics have been studied.