Accession Number : ADA334762

Title :   Particle Dispersion and Inter-Phase Kinetic Energy Transfer in a Turbulent, Two-Phase Shear Layer

Descriptive Note : Final rept.

Corporate Author : AIR FORCE RESEARCH LAB BOLLING AFB DC

Personal Author(s) : Kiger, Kenneth T.

PDF Url : ADA334762

Report Date : 1995

Pagination or Media Count : 181

Abstract : The transport of heavy, polydispersed particles and the inter-phase transfer of kinetic energy is measured experimentally in a turbulent shear layer. Specifically, fundamental/subharmonic forcing and conditional-averaging techniques were used to study the particle/turbulence interaction with the large-scale, spanwise, coherent vortices, starting from their initial roll-up through the first pairing event. It is shown that the pairing event plays a homogenizing role on the particulate field, but the amount of homogenization is strongly dependent upon the particle's viscous relaxation time, the eddy turnover time, as well as the time the particles are allowed to interact with each scale prior to a pairing event. Thus, even though the smaller size particles become well-mixed across the structure, the larger sizes are still dispersed in an inhomogeneous fashion. The dispersed/carrier phase coupling was examined through the measurement of conditionally-averaged kinetic energy transfer (which results from the work done to accelerate or decelerate the dispersed phase), as well as the conditionally-averaged particle dissipation (energy dissipated by shear deformation in the carrier phase due to the relative slip between the particles and the carrier fluid).

Descriptors :   *TURBULENCE, *PHASE STUDIES, *VORTICES, *FLOW FIELDS, *KINETIC ENERGY, *PARTICULATES, SHEAR PROPERTIES, COUPLING(INTERACTION), DISPERSING, SIZES(DIMENSIONS), INTERACTIONS, LAYERS, DEFORMATION, COHERENCE, THESES, PARTICLES, FLUIDS, RELAXATION TIME, VISCOSITY, TWO PHASE FLOW, HOMOGENEITY, DISPERSIONS.

Subject Categories : Physical Chemistry
      Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE