Abstract
Actuator discs may be used as a simple method for simulating horizontal axis tidal turbines, both in experiments and CFD models. They produce a similar far wake to a real turbine, but eliminate some of the scaling issues which occur in experiments, and reduce the mesh density required in CFD simulations. This paper examines methods for applying a simple actuator disc in a commercial CFD code, Ansys CFX, and compares the wake produced with experimental results for similar values of disk thrust coefficient (CT). The results show that the CFD model gives reasonable agreement with the experimental results. The main factors affecting the wake structure are the initial CT value, the ambient turbulence levels, and potentially the disc induced turbulence. The main differences between the models and experiments were in terms of the turbulence levels throughout the model. With further development, it is considered that the CFD actuator disc could be an accurate and validated method for numerically modelling tidal turbines.