
Accession Number : ADA190606
Title : DenseSpray Structure and Phenomena. Part 1. Turbulence/DispersedPhase Interactions.
Descriptive Note : Annual rept. 15 Jul 8614 Jul 87,
Corporate Author : MICHIGAN UNIV ANN ARBOR GAS DYNAMICS LABS
Personal Author(s) : Parthasarathy, R N ; Faeth, G M
PDF Url : ADA190606
Report Date : 15 Aug 1987
Pagination or Media Count : 81
Abstract : This report describes one aspect of an investigation of densespray processes: namely turbulence/dispersedphase interactions. The work was divided into two phases: (1) measurements of particleladen jets injected into a still liquid; and homogenous particle flows, consisting of particles falling in a still (in the mean) liquid bath. The structure of turbulent, dilute, particleladen water jets, submerged in still water, was studied both experimentally and theoretically. Nonintrusive measurements were made of mean and fluctuating phase velocities and particle number fluxes. Analysis was used to help interpret the measurements, considering three limiting cases, as follows: (1) locallyhomogenous flow, where relative velocities between the phases are ignored; (2) deterministic separated flow, where relative velocities are considered, but particle/turbulence interactions are ignored; and (3) stochastic separated flow, where both phenomena are considered using randomwalk methods. The locallyhomogenous flow approximation was more effective than for past work involving larger density ratios between the phases; nevertheless, stochastic analysis yielded best agreement with measurements. Effects of enhanced drag (due to high relative turbulent intensities of particle motion) and effects of particles on liquid turbulence properties (turbulence modulation), were observed. Several recent proposals for treating these phenomena were examined; however, none appears to be adequate for reliable general use.
Descriptors : *WATER JETS, *TWO PHASE FLOW, *DISPERSING, BATHS, DENSITY, DETERMINANTS(MATHEMATICS), DRAG, FLOW, FLOW SEPARATION, HIGH RATE, HOMOGENEITY, INTENSITY, INTERACTIONS, LIMITATIONS, LIQUIDS, MODULATION, MOTION, PARTICLE COLLISIONS, PARTICLE FLUX, PARTICLES, PHASE, RATIOS, STOCHASTIC PROCESSES, TURBULENCE, VELOCITY, WATER, SPRAYS
Subject Categories : Fluid Mechanics
Distribution Statement : APPROVED FOR PUBLIC RELEASE