ISSN Online: 2377-424X
ISBN Print: 0-89116-299-2
International Heat Transfer Conference 7
CRYODEPOSIT MASS TRANSFER AT NEAR VACUUM IN NONISOTHERMAL ENCLOSURES
摘要
An analytical formulation is presented for calculating free molecular mass transport among surfaces of a non-isothermal enclosure. An engineering model of arbitrary geometrical complexity is used to develop algebraic expressions which take into account the temperatures of a surface and the incident molecular flux density to determine whether molecules stick (i.e., condense) or are reflected. It is shown that molecular interchange coefficients are constant so long as surfaces maintain a specified temperature order but coefficients must be re-evaluated each time the order changes. A numerical example illustrates how the formulation may be used to calculate the condensation/ evaporation history of an enclosure with unsteady temperature.