Some Measurements of the Dispersion of Spheres in a Turbulent Flow

摘要

The dispersion of small spherical particles in a grid generated turbulent flow was investigated. Particles were injected singly into the flow without inducing an appreciable disturbance. A detection method utilizing photo multiplier tubes and light fields was devised. The particles used in the experiment were foamed polystyrene of 0.7 and 0.9 millimeter diameter and soap bubbles of 1.25 millimeter diameter. A fine heated wire was used to 'tag' fluid particles in order to obtain Lagrangian data on the flow. Diffusion coefficients, particle velocity auto correlation in time functions, integral and micro-scales were obtained from the data. (Author)