In September 2015 Johanna began as a PhD student at the division of Fluid dynamics. In the project she is studying the flow field around an offshore wind turbine. Her main supervisor is Lars Davidson.Wind turbines placed onshore and offshore placed on the sea bed has been around for some time. At water depths larger than 40 m, the economic advantages turn from putting the wind turbine on the sea bed to putting it on a floating platform. Depths like this represent a large part of the water areas around the world which could be used for offshore windpower. To be able to use these areas further research is needed to simulate the behavior of floating wind turbines.Floating wind turbines at deep waters present an important and interesting modeling challenge as dynamic response depend on several factors including loads from wind, waves, currents, mooring, effects from elastic deformations and the control system. Thus, floating offshore wind turbines (FOWT) present an interesting interdisciplinary research challenge. There exist several codes aimed for simulation of FOWT:s but most use simplified approaches to the flow around the turbine blades (Blade Element Method), for the waves (linear wave theory) and for mooring. There is a need for more advanced tools using Computational Fluid Dynamics (CFD) for both wind and wave loads as well as non-linear methods for mooring.The project is a collaboration between the department of Applied Mechanics and Shipping and Marine Technology at Chalmers. Johanna simulates the flow field around the wind turbine using Large Eddy Simulation (LES). The software used is OpenFOAM coupled to the aeroelastic solver FAST. This is done by SOWFA which is a set of solvers, turbine models and boundary conditions in OpenFOAM. This allows the user to simulate the wind turbine in an atmospheric boundary layer taking the forces from waves and mooring into account. Both the software SOWFA and FAST are made by NREL. In this project SOWFA will be further developed for floating wind turbines.