A CFD Analysis of Wind Effects on Lifted Loads

This work presents a numerical investigation of the effects of wind blowing on lifted structures. The chosen case is an offshore oil & gas platform module lifted by a crane. The pendulum-like displacement of the lifted load is expected once wind blows on it, therefore a pendulum-like displacement is determined via a finite difference scheme whereas drag coefficients of the platform module are estimated through Computational Fluid Dynamics (CFD) via a finite volume method. Numerical results are compared to empirical data found in the literature and experiments carried out in a scaled model. Displacements of the lifted load are calculated for different gusts of wind and compared to standards commonly used by the oil & gas industry. It is confirmed that the recommended horizontal gap around the lifted structure is adequate for wind speeds of up to 20 m/s. For higher wind velocities, displacements become too large for a safe rigging and hook-up operation.