Articles techniques et présentations

During examination of molecular gas flow in freeze dryers in near-vacuum properties, an idea came up to model a molecular fish trap nozzle. An appropriate shape of this fish trap nozzle allows to separate free flowing molecules into 2 chambers, and obtain a pressure gain in a isothermal environment (molecular flow “diode”). While particles don't change their magnitude of momentum after reflection at the walls, observed separation can be considered as isothermal compression. In the first point of view this behavior conflicts with the Second Law of Thermodynamics. But this is not the case. By focusing this problem on stochastic (molecular flow) scale, and not on continuum gas mechanics, there is no problem with any physics laws.