Optical Properties and Aerodynamic Drag Characteristics of Blow-Off Particulates.
Technical rept. 15 Jun 84-31 Jul 85,
WASHINGTON UNIV SEATTLE
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The results of the third and last phase of baseline studies on the electromagnetic scattering properties of the dust particles generated in simulated nuclear explosions and the aerodynamic drag characteristics of the particles are presented. The complex refractive indices and particle sizes were measured by light scattering in the visible range of the electromagnetic spectrum. It was not possible to extend the measurements into the ultraviolet region with the available equipment. Single particle albedos were determined from the light scattering results. A new technique was developed and applied to measure the drag force on single particles suspended in a laminar gas jet, and results are reported for the ratio of the drag force to the particle weight as a function of the particle Reynolds number. It is shown that the optical properties are consistent with data for bulk silicates and that the particles are sufficiently near-spherical to use well established results for spheres in drag force computations.