Accession Number:

AD0668849

Title:

LIGHT SCATTERING EXPERIMENTS AND THE THEORY OF HOMOGENEOUS NUCLEATION IN CONDENSING SUPERSONIC FLOW,

Descriptive Note:

Corporate Author:

YALE UNIV NEW HAVEN CONN DEPT OF ENGINEERING AND APPLIED SCIENCE

Personal Author(s):

Report Date:

1968-03-01

Pagination or Media Count:

24.0

Abstract:

Experimental results of condensation of water vapor by homogeneous nucleation are shown. A supersonic nozzle is used for expanding moist air. Condensation sets in at high initial supersaturation and is initiated by homogeneous nucleation. By standard gasdynamic measurements, in conjunction with a solution of the equations of motion, the thermodynamic state in the condensation zone and the bulk properties of the condensate can be determined. Near 220K finely dispersed small ice clusters were found . Direct measurements of the number of clusters using a helium - neon laser light scattering system are performed. A textbook situation of Rayleigh light scattering prevails. By two different methods a comparison of experimental results may be made with the theory of homogeneous nucleation. In addition cluster growth is discussed since it enters one of the comparisons. Within certain margins of error on properties of the critical nuclei, in particular their surface free energy, the results agree well with the classical theory of Volmer et al. Author

Subject Categories:

  • Aerodynamics
  • Physical Chemistry
  • Fluid Mechanics
  • Thermodynamics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE