The Knudsen pump also referred to as "thermal transpiration pump" or "Knudsen compressor" is a gas
pump
A pump is a device that moves fluids (liquids or gases), or sometimes Slurry, slurries, by mechanical action, typically converted from electrical energy into hydraulic or pneumatic energy.
Mechanical pumps serve in a wide range of application ...
that utilizes no
moving parts
Machines include both fixed and moving parts. The moving parts have controlled and constrained motions.
Moving parts are machine components excluding any moving fluids, such as fuel, coolant or hydraulic fluid. Moving parts also do not include ...
. Instead it uses
thermal transpiration, the phenomenon that gas molecules drift from the hot end to the cold end of a narrow channel. Thus a hot vacuum chamber "transpires" into the cold chamber. This
thermal transpiration flow is induced when the boundary walls of the pump have a temperature gradient. Because the pump is based simply on temperature differences and has no moving parts, it could provide reliable and precise control of gas flow for a variety of applications, such as gas-sensing breath analyzers,
chemical weapons
A chemical weapon (CW) is a specialized munition that uses chemicals formulated to inflict death or harm on humans. According to the Organisation for the Prohibition of Chemical Weapons (OPCW), this can be any chemical compound intended as ...
detectors, and in
satellite
A satellite or an artificial satellite is an object, typically a spacecraft, placed into orbit around a celestial body. They have a variety of uses, including communication relay, weather forecasting, navigation ( GPS), broadcasting, scient ...
control.
It is named after
Martin Knudsen
Martin Hans Christian Knudsen (15 February 1871 in Hasmark on Funen – 27 May 1949 in Copenhagen) was a Danish physicist who taught and conducted research at the Technical University of Denmark.
He is primarily known for his study of molecul ...
, a Danish physicist.
References
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Pumps