Optimal Support Placement for VIV Mitigation in Subsea Rigid Pipelines

Abstract

This study presents an optimization approach for determining the placement of supports to mitigate vortex-induced vibrations (VIV) in free spans of subsea rigid pipelines. Free spans caused by seabed irregularities can critically compromise the pipeline’s structural integrity. To address this challenge, the proposed methodology integrates numerical modeling based on the Finite Element Method (FEM), following the recommendations outlined in DNV-RP-F105, with discrete optimization techniques, namely, a metaheuristic genetic algorithm and a deterministic branch-and-bound algorithm. The objective function minimizes support installation costs by assigning specific penalties to each free span and incorporating constraints related to the pipeline's natural frequency. Results show that the framework is efficient, with the branch-and-bound algorithm consistently reaching optimal solutions while avoiding the variability inherent in stochastic approaches.