|
In aeronautics and marine hydrodynamics, the ''advance ratio'' at which a propeller is operating is the ratio between the distance the propeller moves forward through the fluid during one revolution, and the diameter of the propeller. When a propeller-driven vehicle is moving at high speed relative to the fluid, or the propeller is rotating slowly, the advance ratio of its propeller(s) is a high number; and when it is moving at low speed, or the propeller is rotating at high speed, the advance ratio is a low number. The advance ratio of a propeller is analogous to the angle of attack of an airfoil. ==Advance ratio== The advance ratio J is a non-dimensional term given by:〔Clancy, L.J. (1975), ''Aerodynamics'', Section 17.2, Pitman Publishing Limited, London. ISBN 0-273-01120-0〕〔(Prof. Z. S. Spakovszky ). "(11.7.4.5 Typical propeller performance )" ''MIT turbines'', 2002. (Thermodynamics and Propulsion, main page )〕 : where : The advance ratio is a means of describing the incoming angle of the fluid relative to the propeller blade. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Advance ratio」の詳細全文を読む スポンサード リンク
|