 | This sectionneeds additional citations forverification. Please helpimprove this article byadding citations to reliable sources in this section. Unsourced material may be challenged and removed. Find sources: "Windage" – news ·newspapers ·books ·scholar ·JSTOR(December 2013) (Learn how and when to remove this message) |
In aerodynamics, firearms ballistics, and automobiles,windage is the effects of some fluid, usually air (e.g., wind) and sometimes liquids, such as oil.
Windage is aforce created on an object byfriction when there is relative movement betweenair and the object.Windage loss is the reduction in efficiency due to windage forces.
For example, electric motors are affected by friction between the rotor and air.[1] Largealternators have significant losses due to windage. To reduce losses,hydrogen gas may be used, since it is less dense.[2]
Causes of windage are:
The term can refer to:
Aerodynamic streamlining can be used to reduce windage.
Hydrodynamic drag is ahydrodynamic effect similar to windage.
Infirearms parlance, windage is thesight adjustment used to compensate for the horizontal deviation of theprojectiletrajectory from the intended point of impact due towind drift orCoriolis effect. By contrast, the adjustment for the vertical deviation is theelevation.
Colloquially, "Kentucky windage" is the practice of holding the aim to theupwind side of the target (also known asdeflection shooting or "leading" the wind) to compensate for wind drift, without actually changing the existing adjustment settings on thegunsight.[3]
Inmuzzleloading firearms, windage is the difference in diameter between the bore and theball, especially inmuskets andcannons.[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]
In automotive parlance, windage is parasitic drag on thecrankshaft due tosump oil splashing on the crank train during rough driving. It can also be 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] Windage is eliminated indry sump designs.
windage musket.