An Experimental Study of Particle-Wall Collision Relating to Flow of Solid Particles in a Fluid

Citation

McLaughlin, Michael Herbert (1968) An Experimental Study of Particle-Wall Collision Relating to Flow of Solid Particles in a Fluid. Engineer's thesis, California Institute of Technology. doi:10.7907/4FV5-JA03. https://resolver.caltech.edu/CaltechETD:etd-09102004-144402

Abstract

NOTE: Text or symbols not renderable in plain ASCII are indicated by [...]. Abstract is included in .pdf document. A preliminary investigation was made into the momentum and energy losses resulting from particle collisions in a fluid with application to particle - fluid two-phase flows. In particular, the length scale over which these intereactions are important was investigated. The geometry chosen for the experiments was that of a sphere approaching an infinite wall, a geometry which tended to maximize the energy and momentum losses of the sphere. The experiments were performed by dropping a steel sphere through a glycerin-water solution onto a steel surface. Flows for which the particle Reynolds number, [...] (based on terminal velocity and particle diameter), ranged from 0.05 to 7870 were investigated by taking high-speed motion pictures. Position-time curves were generated, and it was shown that above a moderate Reynolds number the important momentum and energy interactions occurred within a fraction of a ball radius of the wall. As the Reynolds number was increased from the Stokes flow regime, the decrease of this interaction length was shown. At higher [...] the viscous losses became an increasingly smaller percent of the particle kinetic energy. A preliminary investigation was made of an alternate test procedure utilizing a thin liquid film rather than the continuum tank. The results showed that a critical film thickness existed, above which the energy loss did not significantly increase with increasing film thickness. The prospects of correlating the continuum loss effects with the thin-film loss effects appeared good and warrant further investigation. Photographic materials on pages 5 and 14 are essential and will not reproduce clearly on Xerox copies. Photographic copies should be ordered.

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