A complete analytical formulation of the vortex approach for the rotor with an ideal load distribution under Betz optimal condition needs some additional assumption about a correct choice of the helical pitch for vortex sheets in the rotor wake. An examination of the three evident assumptions (the pitch is independent from velocities induced by the wake; the pitch depends on the induced velocities in the far wake; the pitch depends on the induced velocities in the rotor plane) was considered by a comparison with the main restriction of the actuator disk theory – the Betz-Joukowsky limit. In the present investigation an analytical solution for the limit case of an infinite number of blades was used to re-examine the choice of the wake pitch.
Journal of Physics: Conference Series (online), 2014, Vol 524, Issue 1
Main Research Area:
5th International Conference on The Science of Making Torque from Wind 2014European Academy of Wind Energy : The Science of Making Torque from Wind