Aero-Hydrodynamic Analysis of an Offshore Floating Multi-Wind-Turbine Platform – Part II

The recent developments in technology have enabled the placing of multiple wind turbines on a single large floating platform that can enhance the renewable energy generation from offshore wind resources. This paper and the corresponding hydrodynamic analysis paper– Part II (also in these proceedings) describes the intermediate results of ongoing research at designing a semi-submersible offshore floating platform for the multiple wind turbine arrangement. The key issues that have been addressed in this paper include modeling the aerodynamic loads due to wind speed on the wind turbines. The configuration of the offshore floating platform to install five 8MW wind turbines modeled in previous work is reviewed. The aerodynamic simulation of the offshore floating multi-wind-turbine platform (OFMWTP) is carried out using the Ansys software. The Reynolds-averaged Navier-Stokes (RANS) equations with the k-o) shear stress transport (SST) turbulence model are used for CFD calculations in Ansys Fluent. A multiple moving reference frame with a sliding mesh technique is used to simulate the rotation of the rotors of the five wind turbines installed on the platform. The pressure, velocity, and turbulence intensity contours of the OFMWTP are evaluated with a focus on the downstream wind turbine as it is in partial wake of the upstream wind turbines. The aerodynamic force of the wind turbines is evaluated to study the aerodynamic performance of the wind turbines. The aerodynamic power is calculated from the simulation and compared with the reference wind turbine value which showed a good agreement. The power deficit at the downstream wind turbine is evaluated and compared with experimental data of a reference which showed that power deficit in the present work is greatly reduced because of the wind turbine size and increased separation between wind turbines.