%I #36 Sep 21 2022 08:34:48

%S 5,9,2,5,9,2,5,9,2,5,9,2,5,9,2,5,9,2,5,9,2,5,9,2,5,9,2,5,9,2,5,9,2,5,

%T 9,2,5,9,2,5,9,2,5,9,2,5,9,2,5,9,2,5,9,2,5,9,2,5,9,2,5,9,2,5,9,2,5,9,

%U 2,5,9,2,5,9,2,5,9,2,5,9,2,5

%N Decimal expansion of 16/27.

%C Betz's constant (or Betz's coefficient): maximum efficiency of a turbine. The constant is unfortunately named; Lanchester discovered it before Betz, and Lanchester cites Froude (though it seems that Lanchester was the first to write it explicitly). Joukowsky (also spelled Zhukovsky) and Munk published discoveries the same year as Betz.

%D Albert Betz, "Das Maximum der theoretisch möglichen Ausnutzung des Windes durch Windmotoren", Zeitschrift für das gesamte Turbinenwesen 26 (1920), pp. 307-309.

%D N. E. Joukowsky (Николай Егорович Жуковский), Windmill of the NEJ type (in Russian), Transactions of the Central Institute for Aero-Hydrodynamics of Moscow (1920). Appeared in Collected Papers Vol VI, The Joukowsky Institute for AeroHydrodynamics, Moscow, Russia (1937); VI: 405-409 (in Russian).

%D F. W. Lanchester, A contribution to the theory of propulsion and the screw propeller, Transactions of the Institution of Naval Architects 57 (1915), pp. 98-116. (See pp. 114-115.)

%H Albert Betz, <a href="https://doi.org/10.1260/0309-524X.37.4.441">The Maximum of the Theoretically Possible Exploitation of Wind by Means of a Wind Motor</a>, Wind Engineering, Vol 37, Issue 4, 2013 (English translation).

%H Max M. Munk, <a href="https://ntrs.nasa.gov/search.jsp?R=19930084029">Wind driven propeller</a>, NACA Technical Memorandums 201 (1920), pp. 1-12 (German original in: Zeitschrift für Flugtechnik und Motorluftschiffahrt August 15, 1920: 220-223)

%H Henry Reich, <a href="https://www.youtube.com/watch?v=CI-bwqhhTTw">Windmills Are NOT Like Dams</a>, minutephysics video (2022).

%H <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (0,0,1).

%F Equals 16 * A021031. - _Felix Fröhlich_, Jun 17 2017

%e 0.5925925925925925925925925925925925925925925925925925925925925925925...

%t RealDigits[16/27,10,120][[1]] (* or *) PadRight[{},120,{5,9,2}] (* _Harvey P. Dale_, Dec 04 2012 *)

%o (PARI) 16/27.

%Y Cf. A021031, A021112.

%K nonn,easy,cons

%O 0,1

%A _Charles R Greathouse IV_, Aug 07 2012