Freezing Water with Sized AgI Particles. Part II: Theoretical Considerations.

Abstract

VELOPED FOR THE HETEROGENEOUS NUCLEATION RATE OF SUPERCOOLED WATER DROPLETS BY THERMALLY GENERATED AgI particles. The rate equations are determined as a function of the AgI particle size, shape, and surface structure, critical embryo shape, temperature, and ice-AgI contact angle in water. The assumptions and approximations inherent in this treatment are evaluated. It was determined that the important assumption of an appreciable nucleation rate is inconsistent with the large uncertainty in the value of the contact angle. As a consequence, classical theory could account for the experimentally determined dependence of activity on the particles' surface area. The appreciable nucleation rate also may not be used in Fletcher's ice-filled pits site theory. It is shown how the statistical nature of the nucleation process provides a method by which classical and site theory may be differentiated. (Author)

Document Details

Document Type
Technical Report
Publication Date
Mar 01, 1973
Accession Number
AD0758858

Entities

People

  • Hermann E. Gerber

Organizations

  • United States Army Communications-Electronics Command

Tags

DTIC Thesaurus Topics

  • Critical Temperature
  • Equations
  • Equations Of State
  • Freezing
  • Glass Transition Temperature
  • Mathematics
  • Nucleation
  • Particle Size
  • Particles
  • Transition Temperature
  • Uncertainty

Readers

  • Aerosol Science/Aerosol Physics
  • Fluid Dynamics.