The Dynamics of Nonspherical Particles. V. The Wall Effect in Orderly Deposition; Brownian Diffusion.
Abstract
The effect of the wall on the motion of elongated aerosol particles was calculated on the basis of the (powerful) slender body theory for a quiet and flowing medium. The cases treated were those of cylindrical particles moving in a quiet environment or a Couette or a Poiseuille flow near plannar surfaces with various inclinations to the horizontal. Experiments of trajectory photographing were performed in a liquid-tank under creeping flow conditions and typical (aerosol) Reynolds numbers whereby very good correspondence with computations was obtained. The Brownian diffusion of (very small) cylindrical or discoidal aerosol particles was also studied while being based on Brenners' formal structure. To evaluate the significant orientation density function, the (mid-diameter) rotational diffusion coefficient of the particles was calculated by a statistical-mechanical method. The values of the coefficients were found to be larger than those computed on the basis of continuum theory by a factor of about 30. The typical diffusion situation of deposition on a plane within a quiet air was treated. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 1981
- Accession Number
- ADA111222
Entities
People
- Isaiah Gallily
Organizations
- Hebrew University of Jerusalem