Some Gasdynamic Problems in the Flow of Condensing Vapors

Abstract

Some Gasdynamic Problems in the Flow of Condensing Vapors. The general problem of the flow
\nof a wet vapor, with or without an inert diluent is formulated under the assumption that the liquid phase
\nis finely divided and dispersed throughout the gaseous component in droplets whose radii are nearly
\nconstant in any local region. The processes of momentum transfer, heat transfer between phases are
\nassumed to take place according to Stokes law and Nusselt number of unity, respectively. The mass transfer
\nprocess is treated as diffusion governed in the presence of an inert diluent and kinetic governed for two
\nphases of a pure substance.
\nThe physical understanding of such problems, in contrast with those of conventional gas dynamics,
\nrests largely in the role played by the relaxation times or equilibration lengths associated with these three
\nprocesses. Consequently, both simple and coupled relaxation processes are examined rather carefully by
\nspecific examples. Subsequently, the problem of near-equilibrium flow in a nozzle with phase change is solved
\nunder the small-slip approximation. The structure of the normal shock in a pure substance is investigated
\nand reveals three rather distinct zones: the gasdynamic shock, the vapor relaxation zone, and the thermal
\nand velocity equilibration zone. The three-dimensional steady flow of the two-phase condensing continuum
\nis formulated according to first order perturbation theory, and the structure of waves in such supersonic flow
\nis examined. Finally, the attenuation of sound in fogs is formulated and solved accounting for the important
\neffects of phase change as well as the viscous damping and heat transfer which have been included in previous
\nanalyses.