ISSN:
0934-0866
Keywords:
Chemistry
;
Industrial Chemistry and Chemical Engineering
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Process Engineering, Biotechnology, Nutrition Technology
Notes:
The paper describes the application of a stochastic separated flow model for the dispersed phase to the prediction of a particle-laden turbulent air jet discharging at 13 m/s from a 15 mm nozzle into stagnant surroundings. Emphasis is placed on the stochastic element of the Lagrangian particle tracking part of the model and on the importance of particle initial conditions over the first 20 jet diameters. Calculations are presented for 80 m̈m sized glass particles which clarify how particles with turbulent Stokes number less than unity acquire axial turbulence much larger than radial. Far from being only a response to the gas-phase turbulence as implied by the model, the axial turbulence is shown to be also produced by an interaction between particle radial turbulence fluctuations and cross-stream spatial gradients in particle mean velocity, here referred to as "fanspreading". In addition, initial particle turbulence levels remain identifiable for about 10 jet diameters; the initial radial turbulence reinforces the fan-spreading contribution and leads to extra generation of axial turbulence farther downstream. In general, the results agree well with experimental measurements.
Additional Material:
3 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/ppsc.19900070134
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