CFD Modeling and Validation of Steel Lazy-Wave Riser VIV

The steel lazy wave riser is an emerging solution for deepwater applications in harsh conditions. The addition of buoyancy to provide the unique “lazy wave” shape reduces the dynamic stresses at the touchdown zone due to vessel motions and waves and results in improved performance. However, as the buoyant region cannot be easily fitted with VIV suppression, VIV becomes a critical aspect of the design. The present study progresses the modeling effort presented in [2] to model and understand the global response of a deepwater lazy wave riser using computational fluid dynamics (CFD). An industry first CFD simulation of a steel lazy wave riser under in-plane currents is presented and validated against experiments with two different configurations. Results show good agreement between CFD and experiments and provide an initial understanding of the riser response under in-plane currents. The CFD method developed has been validated and will be an important tool for the design of lazy wave risers.