is a surface used to produce thrust
by travelling in water
or another liquid
media. The first use of the word was for the limbs of fish
, but has been extended to include other animal limbs and man made devices.
The foremost use of fins are to propel an object through lateral thrust (see mechanics).
Fin construction is complicated and very tightly associated with the science of hydrodynamics. Fin construction is much centered around avoiding cavitation.
Examples of fin use:
- Propellers usually have a number of fins that work to translate tourquing force to lateral thrust, thus propelling a ship.
Constructions of the same purpose as fins, but working in gaseous media instead are generally called wings
as the governing science. The exception to this is the vertical surface of an aircraft to which the rudder
is attached - this is still usually called a fin.
is also a slang term for a five dollar note.