Knudsen gas

A Knudsen gas is a model for gases where particle collisions are ignored, as opposed to the Lorenz gas where collisions are considered. In these gases the distance between molecules are bigger than the recipient where the gas is contained. A flow of gas through a pipe is called Knudsen when it can be expressed as the difference of two independent flows, which enter to the pipe through its different ends.

See also

• Kinetic theory