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Criteria for significance of simultaneous presence of both condensible vapors and aerosol particles on mass transfer (deposition) ratesThe simultaneous presence of aerosol particles and condensible vapors in a saturated boundary layer which may affect deposition rates to subcooled surfaces because of vapor-particle interactions is discussed. Scavenging of condensible vapors by aerosol particles may lead to increased particle size and decreased vapor mass fraction, which alters both vapor and particle deposition rates. Particles, if sufficiently concentrated, may also coagulate. Criteria are provided to assess the significance of such phenomena when particles are already present in the mainstream and are not created inside the boundary layer via homogeneous nucleation. It is determined that there is direct proportionality with: (1) the mass concentration of both condensible vapors and aerosol particles; and (2) the square of the boundary layer thickness to particle diameter ratio (delta d sub p) square. Inverse proportionality was found for mainstream to surface temperature difference if thermophoresis dominates particle transport. It is concluded that the square of the boundary layer thickness to particle diameter ratio is the most critical factor to consider in deciding when to neglect vapor-particle interactions.
Document ID
19880023744
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Gokoglu, S. A.
(NASA Lewis Research Center Cleveland, OH, United States)
Date Acquired
August 13, 2013
Publication Date
January 1, 1987
Subject Category
Engineering (General)
Meeting Information
Meeting: 1987 ASME/JSME Thermal Engineering Joint Conference
Location: Honolulu, HI
Country: United States
Start Date: March 22, 1987
End Date: March 26, 1987
Accession Number
88A10971
Distribution Limits
Public
Copyright
Other

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