1 Department of Mechanical Engineering, Technical University of Denmark 2 Fluid Mechanics, Department of Wind Energy, Technical University of Denmark 3 Department of Wind Energy, Technical University of Denmark 4 Delft University of Technology 5 Delft University of Technology
The derivation of the efficiency of an ideal wind turbine has been attributed to the three famous scientists of the three aerodynamic research schools in Europe during the first decades of the previous century: Lanchester, Betz and Joukowsky. However, detailed reading of their classical papers has shown that Lanchester did not accept Froude's result that the velocity through the disc is the average of the velocities far upstream and far downstream, by which his solution is not determined. Betz and Joukowsky used vortex theory to support Froude's result and derived the ideal efficiency of a wind turbine at the same time. This efficiency has been known as the Joukowsky limit in Russia and as the Betz limit everywhere else. Because of the contribution of both scientists, this result should be called the Betz–Joukowsky limit everywhere. Copyright © 2011 John Wiley & Sons, Ltd.
Wind Energy, 2012, Vol 15, Issue 2, p. 335-344
Betz limit; Actuator disc theory; Vortex theory; Wind turbine
Main Research Area: