Programme details

The traditional method for analysing subsea lifts is based on a number of simplifications which can result in conservative estimate of peak loads and very low installation seastates. As structures become increasingly larger and more complex, more advanced methods of structure installation analysis are required to ensure safe and efficient installation and full utilisation of vessel capacity. The presentation will give an overview on how subsea lifts can be analyzed in the time domain and how in combination with Computational Fluid Dynamics (CFD), the lifting operation can be significantly optimised. CFD is first used to estimate the hydrodynamic coefficients of the lifted object by applying forced harmonic oscillations in the software Ansys CFX. The obtained coefficients are subsequently used as input to the time domain analysis performed with the software SIMO (Simulation of Marine Operations). The complete lifting operation from lift off from deck, lowering through the splash zone and down to landing at the sea bottom can be simulated. Reference will be made to the new DNV Recommended Practice for Modelling and Analysis of Marine Operations, DNV-RP-H103.