Cryodeposit mass transfer at near vacuum in nonisothermal enclosures
Abstract
An analytical formulation is presented for calculating free molecular mass transport among surfaces of a nonisothermal 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 specifield temperature order but coefficients must be reevaluated 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.
 Publication:

Heat Transfer 1982, Volume 2
 Pub Date:
 1982
 Bibcode:
 1982hetr....2..469B
 Keywords:

 Cryodeposits;
 Mass Transfer;
 Spacecraft Environments;
 Vacuum Deposition;
 Algebra;
 Evaporation;
 Free Molecular Flow;
 Mass Balance;
 Nonisothermal Processes;
 Surface Properties;
 Fluid Mechanics and Heat Transfer