Windage
Windageis a term used in aerodynamics, firearms ballistics, and automobiles that mainly relates to the effects of air (e.g., wind) on an object of interest. The term is also used for the similar effects of liquids, such as oil.
Usage
[edit] | This sectionneeds additional citations forverification.(December 2013) |
Aerodynamics
[edit]Windageis aforcecreated on an object byfrictionwhen there is relative movement betweenairand the object.Windage lossis the reduction in efficiency due to windage forces.
For example, electric motors are affected by friction between the rotor and air.[1]Largealternatorshave significant losses due to windage. To reduce losses,hydrogen gasmay be used, since it is less dense.[2]
There are two causes of windage:
- The object is moving and being slowed byresistancefrom the air.
- Awindis blowing, producing aforceon the object.
The term can refer to:
- The effect of the force, for example the deflection of a missile or an aircraft by a cross wind.
- The area and shape of the object that make it susceptible to friction, for example those parts of aboatthat are exposed to the wind.
Aerodynamicstreamliningcan be used to reduce windage.
There is ahydrodynamiceffect similar to windage,hydrodynamic drag.
Ballistics
[edit]Infirearmsparlance, the wordwindagerefers to thesightadjustment used to compensate for the horizontal deviation of theprojectiletrajectoryfrom the intended point of impact due towind driftorCoriolis effect.By contrast, the adjustment for the vertical deviation is theelevation.
The colloquial term "Kentucky windage" refers to the practice of holding the aim to theupwindside of the target (also known asdeflection shootingor "leading" the wind) to compensate for wind drift, without actually changing the existing adjustment settings on thegunsight.[3]
Inmuzzleloadingfirearms,windagealso refers to the difference in diameter between the bore and theball,especially inmusketsandcannons.[4]The bore gap allows the shot to be loaded quickly, but reduces the efficiency of the weapon'sinternal ballistics,as it allows gas to leak past the projectile. It also reduces the accuracy, as the ball takes a zig-zag path along the barrel, emerging out of the muzzle at an unpredictable angle.[5]
Automobiles
[edit]In automotive parlance, windage refers to parasitic drag on thecrankshaftdue tosumpoil splashing on the crank train during rough driving, as well as dissipating energy in turbulence from the crank train moving the crankcase gas and oil mist at high RPM. Windage may also inhibit the migration of oil into the sump and back to the oil pump, creating lubrication problems. Some manufacturers and aftermarket vendors have developed special scrapers to remove excess oil from the counterweights and windage screens to create a barrier between the crankshaft and oil sump.[6][7]
See also
[edit]References
[edit]- ^Xdot Engineering and Analysis with Computer Aided Engineering Associates (24 August 2015)."Electrical Machinery Windage Loss"(PDF).CAE Associates.Retrieved2019-05-29.
- ^"Advantages of Hydrogen Cooling in Generators".Archived fromthe originalon 2019-05-29.Retrieved2019-05-29.
- ^Hendrickson, Robert (2000).The Facts on File Dictionary of American Regionalisms.Infobase Publishing.ISBN9781438129921.
- ^Kingsbury, Charles P. (1849).An elementary treatise on artillery and infantry.New York: GP Putnam. p. 59.OCLC761213440.
- ^Kennedy, John Clark (1855).The Theory of Musketry.p.27.Retrieved2019-05-29– via Internet Archive.
windage musket.
- ^"What is a crank scraper".
- ^"Oil Pan Design Oil Windage Tech - Overview Circle Track Magazine".circletrack.Archived fromthe originalon 2007-08-25.