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ISSN Online: 2377-424X

ISBN CD: 1-56700-226-9

ISBN Online: 1-56700-225-0

International Heat Transfer Conference 13
August, 13-18, 2006, Sydney, Australia

CONDENSATION-RELAXATION OF SUPERSATURATED VAPOR AND THE POSSIBILITY OF THE EXPERIMENTAL DETERMINATION OF THE NUCLEATION RATE

Get access (open in a dialog) DOI: 10.1615/IHTC13.p25.70
12 pages

Résumé

In this paper, we propose a method for determining the nucleation rate immediately at the drop nucleation step. The method was developed by analysing the results of numerical modelling by moment's method of the bulk condensation of vapor from a vapor—gas mixture after instantaneous creation of a supersaturated state with regard to heat release. The assumption of equality of temperatures of drops and vapour is used. The analysis of the numerical modelling results enabled us to make simplifying assumptions and derive scaling relations, which relate the condensation relaxation time and the number density of drops to the nucleation rate under initial conditions. It is these relations, who provide a fundamental possibility of experimentally determining the nucleation rate, form the basis for the method proposed. Use of the received relations as theoretical basis for experiments has demanded the analysis of assumptions at which they have been received, in particular, the assumption that one can ignore drop nucleation and growth at the step of rapid attainment of a supersaturated state, which precedes relaxation. For this purpose, in last section, we also consider two modes -static and dynamic- of condensation relaxations, not doing this assumption. The received results allow determining the conditions of applicability of scaling relations. Namely, the received results specify an expansion rate at which the scaling relations can be used for experimental determining of nucleation rate.