Accession Number : AD0717217

Title :   Particle Dispersion Study.

Descriptive Note : Final rept.,

Corporate Author : THIOKOL CHEMICAL CORP HUNTSVILLE ALA HUNTSVILLE DIV

Personal Author(s) : Pritts,O. R.

Report Date : OCT 1970

Pagination or Media Count : 60

Abstract : The program involved experimental observation of dispersion phenomena when particulate matter contained in a subsonic turbulent jet mixes coaxially with another subsonic stream. Experimental variables included particle size, particle flow rate, gas flow rate, and jet molecular weight. Primary gas (e.g., air or helium) entraining the particulate matter was introduced on the centerline of a secondary chamber in which a subsonic turbulent air stream had been established. Particle concentrations at discrete radial and axial locations in the mixing zone were determined. Also when helium was used in the primary stream, helium concentration in the mixing zone was determined. Results showed that the 1 micron diameter particles diffuse at the same rate as the central jet when the central jet is air. Changing the central jet carrier gas from air to helium did not affect particle diffusion rates as predicted by most current theories which assume that particle transport is dependent upon gas momentum transport. Conversely, these data show that particle transport is independent of gas momentum transports. Results using glass beads showed very high diffusion rates, adverse to that expected. It is postulated that this rapid diffusion is due to an electrostatic field established by interaction between the beads themselves and between the beads and plastic chamber walls. (Author)

Descriptors :   (*PARTICLES, SCATTERING), (*JET MIXING FLOW, TRANSPORT PROPERTIES), SUBSONIC FLOW, PARTICLE SIZE, SECONDARY FLOW, HELIUM, AIR, MOMENTUM, TURBULENCE, TWO PHASE FLOW

Subject Categories : Aerodynamics
      Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE