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The dispersion of discrete particles in a turbulent fluid field
Author(s) -
Calabrese Richard V.,
Middleman Stanley
Publication year - 1979
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.690250614
Subject(s) - turbulence , dispersion (optics) , exponential function , mechanics , particle (ecology) , neutral buoyancy , autocorrelation , physics , magnetosphere particle motion , degree (music) , flow (mathematics) , classical mechanics , mathematics , optics , mathematical analysis , statistics , geology , magnetic field , oceanography , acoustics , quantum mechanics
The degree of radial dispersion of medium size particles (η K < d p < l f ) emanating from a point source, is measured photographically in the turbulent core of a fully developed vertical pipe flow of water. From the classical theoretical results of G. Taylor, it was then possible to calculate statistical parameters which characterize the turbulent particle motion. A comparison is made between a tracer and neutrally dense, buoyant and heavy particles. Results indicate that the effect of particle intertia is negligible, and that the crossing trajectories effect dominates the dispersion process. A “wake effect” causes a buoyant particle to disperse to a greater degree than an equivalent heavy particle. An exponential‐cosine form of the Lagrangian autocorrelation coefficient provides a best fit for the dispersion data, although a purely exponential form is equally adequate for practical calculations.