FOWT Hybrid Substructure Analyses: A comparison between Orcaflex and Sima software

Abstract

The usage of SESAM modules to estimate the responses of a hybrid substructure from a given set of boundary conditions. The substructure model which was given by Bassoe Technology will be analyzed. Initially three models are presented, the Panel Model, Morison Model and Mass Model. The Panel Model gives physical information about the Substructure (i.e., displaced volume, shape, etc....). The Morison Model incorporates the second order wave loads on a structure which come from drag and inertial effects such as viscous effects or turbulence. The Mass Model gives data about the mass of each individual element. When these models are introduced to SESAM environment, taken as FEM files and ran on GeniE to be able to be imported into other models. The WADAM wizard in Hydro-D must be run to get the required data so that an analysis in Sima can be done. The WADAM will be using predefined environmental data and the panel, model, and mass models. The WADAM will output all the Kinetics and GDF Geometry required in Sima. Sima will be run to get the non-linear motions and station keeping analysis. The same analysis was run in ORCAFLEX with generated wind data using Turbosim. The ORCAFLEX and Sima carry out the same simulation with different types of inputs. These simulations are carried out to understand the mooring system stresses forces as well as WASIM export to understand the sectional loads. The Sima simulation uses a uniform wind model while ORCAFLEX uses generated values. At the end of these simulations, the results are compared to analyze the methodology used.