The Lanchester-Betz-Joukowsky limit

The maximum efficiency of an ideal wind turbine rotor is well known as the 'Betz limit', named after the German scientist that formulated this maximum in 1920. In 1976, Bergey showed that the British scientist Lanchester derived the some maximum already in 1915. Betz and Lanchester were representatives of leading aerodynamic research schools in the first decades of the previous century. A study of early Russian publications on rotor aerodynamics now shows that the Russian aerodynamic school also produced the same result; its leader Joukowsky derived the maximum efficiency for an ideal wind turbine in 1920, the same year as Betz did. Consequently, in order to honour all, this ideal efficiency should be named the 'Lanchester-Betz-Joukowsky limit' in scientific writing. The well-established and convenient name Betz limit is to be considered an easy abbreviation of this full name. Copyright (C) 2007 John Wiley & Sons, Ltd.