Thermophoretically augmented mass-, momentum-, and energy-transfer rates in high particle mass-loaded laminar forced convection systems
In all previous treatments of thermophoretically-modified aerosol particle transport, even those which attempt to allow for variable host-gas properties, it has been explicitly (or implicitly) assumed that the particle mass fraction is small enough to neglect the influence of the suspended particles on the host-gas momentum-density- and energy-density-fields. However, in high-intensity material-processing applications, particle mass loadings often exceed 1/3, and the thermophoretically enhanced particle mass-deposition flux itself modifies the local-mixture velocity and temperature fields in the vicinity of the deposition surface. A self-consistent pseudo- single-phase mixture (diffusion) approximation which exploits the fact that the volume fraction of suspended particles is negligible even when the particle mass fraction is quite near unity is introduced to calculate the fully coupled problem of mass-, energy- and momentum diffusion for laminar boundary (LBL) flow of a combustion-gas mixture containing submicron particles of appreciable thermophoretic diffusivity but negligible Brownian diffusion. It is shown that thigh particles mass loading systematically increase the wall fluxes of momentum (shear stress), heat and particle mass, much like those effects associated with massive suction in single-phase LBL-theory.
- Research Organization:
- Yale Univ., New Haven, CT (USA)
- OSTI ID:
- 6474637
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
420400* -- Engineering-- Heat Transfer & Fluid Flow
500200 -- Environment
Atmospheric-- Chemicals Monitoring & Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
AEROSOLS
COLLOIDS
CONVECTION
DISPERSIONS
ENERGY TRANSFER
FLUID FLOW
FORCED CONVECTION
HEAT TRANSFER
LAMINAR FLOW
MASS TRANSFER
MOMENTUM TRANSFER
PARTICLES
PARTICULATES
SOLS
THERMOPHORESIS
TOTAL SUSPENDED PARTICULATES
TRANSPORT THEORY