The Dynamics of Non Spherical Particles.
Abstract
In this paper the aerodynamic translational mobility of nonsphericals was experimentally determined for Knudsen numbers of up to 0.2. The particles were glass cylinders, which represent asbestos fibers and ice needles, and cubes, which represent the primary constituents of metal oxide aggregates. The method of determination and the apparatus used were based on a stereophotography of the trajectories of the particles in still air and a photogrammetric measurement of the (three) dimensions of the particles in a scanning electron microscope. The results for cylinders, compared with continuous fluid theoretical values of the coefficients, show a reasonable correspondence with expectation which even improved when the blunt edge effect of the particles was taken into consideration. However, in the case of cylinders having diameters above 1 micrometers, the experimentally determined coefficients were higher by about 50% than the continuous fluid calculated ones, whereas in the case of cylinders of diameters less than 0.5 micrometers, the determined coefficients were smaller than the calculated values. The resistance coefficients of cubes showed similar tendencies. The deposition of cylindrical particles in still air was studied in a specially constructed sedimentation cell; in this cell, a method for the size distribution analysis of these particles was tried.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1977
- Accession Number
- ADA047144
Entities
People
- Isaiah Gallily
Organizations
- Hebrew University of Jerusalem