Blade pitch

Blade pitch

Blade pitch or simply pitch refers to turning the angle of attack of the blades of a propeller into or out of the wind to control the production or absorption of power. Wind turbines use this to adjust the rotation speed and the generated power. A propeller of a ship uses this effect to control the ship's speed without changing the rotation of the shaft and to increase the efficiency of streaming fluids.

In aircraft, blade pitch is usually described as "coarse" for a high angle of attack, and "fine" for a low angle of attack.

Blade pitch is normally described in units of distance/rotation assuming no slip.

Blade pitch acts much like the gearing of the final drive of a car. Low pitch yields good low speed acceleration (or climb rate in an aircraft) while high pitch optimizes high speed performance and economy.

Because the velocity of a propeller blade varies from the hub to the tip, they must be of twisted form in order for the pitch to remain constant along the length of the blade. This is typical of all but the crudest propellers.

It is quite common in aircraft for the propeller to be designed to vary pitch in flight, optimizing both cruise and takeoff performance.

External links

* [http://www.caravelleboats.com/propeller%20info.htm Understanding your Propeller] - includes a description of blade pitch


Wikimedia Foundation. 2010.

Игры ⚽ Поможем написать реферат

Look at other dictionaries:

  • blade pitch — menčių žingsnis statusas T sritis Energetika apibrėžtis Atstumas tarp mentinės mašinos menčių, pritvirtintų ant darbinio rato. atitikmenys: angl. blade pitch; blade spacing vok. Schaufelteilung, f rus. шаг лопаток, m pranc. pas de l’aubage, m;… …   Aiškinamasis šiluminės ir branduolinės technikos terminų žodynas

  • blade pitch angle — The angle between the chord of the blade and the reference line on the rotor hub …   Aviation dictionary

  • propeller blade pitch — The distance a propeller will advance if there is no slip. See blade pitch angle …   Aviation dictionary

  • Pitch — may refer to:In music: * Pitch (music), the property of a sound or musical tone measured by its perceived frequency ** Range (music), the distance from the lowest to the highest pitch a musical instrument can play ** Vocal range, the distance… …   Wikipedia

  • blade spacing — menčių žingsnis statusas T sritis Energetika apibrėžtis Atstumas tarp mentinės mašinos menčių, pritvirtintų ant darbinio rato. atitikmenys: angl. blade pitch; blade spacing vok. Schaufelteilung, f rus. шаг лопаток, m pranc. pas de l’aubage, m;… …   Aiškinamasis šiluminės ir branduolinės technikos terminų žodynas

  • pitch — pitch1 [pich] n. [ME pich < OE pic < L pix (gen. picis) < IE base * pi , to be fat > FAT] 1. a black, sticky substance formed in the distillation of coal tar, wood tar, petroleum, etc. and used for waterproofing, roofing, pavements,… …   English World dictionary

  • pitch — I n. high pressure sales talk (colloq.) 1) to deliver a pitch 2) a sales pitch blade angle 3) a propeller pitch 4) reverse pitch intensity 5) a fever; high; low pitch (to reach a fever pitch) throw of a baseball (esp. AE) …   Combinatory dictionary

  • blade twist — i. The undesirable variation in pitch from root to tip caused by aerodynamic loading. ii. The twist built into a propeller or rotor blade. In the case of a propeller, it is to ensure that the pitch angle at the root is greater than the tip. In… …   Aviation dictionary

  • Pitch.Black.Effects — Infobox Album Name = [Pitch.Black.Effects] Type = studio Artist = Callenish Circle Released = November 14, 2005 Recorded = Genre = Melodic death metal Length = 43:22 Label = Metal Blade Producer = Reviews = * Allmusic Rating|3.5|5… …   Wikipedia

  • pitch — i. The rotation of an aircraft about its lateral axis. ii. The distance a propeller will advance in one revolution if there is no slip. Also called a propeller pitch. iii. The angular setting of a helicopter main or tail rotor blade relative to… …   Aviation dictionary

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”