Paper Title
6DOF Prediction of Two Blades H-Darrieus Wind Turbine Efficiency

Abstract
The present paper investigates the aerodynamic performances variations of straight-blades DARRIEUS wind turbine in two-dimensional steady flow with different low Reynolds numbers (30k, 40k, 55k and 80k). The numerical 6DOF approach (six degrees of freedom) is used to predict sequentially the angular positions according to the wind turbine mass properties (mass and moment of inertia) in real time. The numerical optimization requires a transient dynamic mesh technique for one degree of freedom around the rotation axis. The self-starting ability of the H-Darrieus wind turbine is expressed by increasing the inlet wind velocity, independently to the wind direction (angles of attack: 0°, 10°, and 20°). A 2D unsteady shear stress transport (SST k- ω) model has been employed to perform the present simulation. The various results of performance coefficients (lift and torque) obtained by a two blades design show a significant agreement with the available experimental data, as well as, an important increase in lift and torque according to the increase of the free stream wind velocity. However, the static stall still at the same azimuthal position (about 11°). That is a consequence of the appropriate modelling of the rotational speed, as well as, the stability that characterizes the 6DOF approach. The tangential force is maximum (wind turbine acceleration), where the blades axis are normal to the velocity field, and neglected at the braking position 0°. Index Terms: Performances, H-Darrieus, Dynamic Mesh, Mass Properties, 6DOF, Lift, SST K- ω.