Accession Number:

ADA254130

Title:

Turbulent Dusty Boundary Layer in an ANFO Surface-Burst Explosion

Descriptive Note:

Technical rept. 1 Oct 1988-31 Dec 1989

Corporate Author:

LOGICON R AND D ASSOCIATES LOS ANGELES CA

Report Date:

1992-08-01

Pagination or Media Count:

52.0

Abstract:

This paper describes the results of numerical simulations of the dusty, turbulent boundary layer created by a surface burst explosion. The blast wave was generated by the detonation of a 600-T hemisphere of ANFO, similar to those used in large-scale field tests. The surface was assumed to be ideally noncratering but contained an initial loose layer of dust. The dust-air mixture in this fluidized bed was modeled as a dense gas i.e., an equilibrium model, valid for very-small-diameter dust particles. The evolution of the flow was calculated by a high-order Godunov code that solves the nonsteady conservation laws. Shock interactions with dense layer generated vorticity near the wall- similar to viscous, no-slip effects found in clean flows. The resulting wall shear layer was unstable, and rolled up into large-scale rotational structures. These structures entrained dense material from the wall layer and created a chaotically striated flow. The boundary layer grew due to merging of the large- scale structures and due to local entrainment of the dense material from the fluidized bed. Surface-Burst Explosions, Convective Mixing Simulations of Turbulent Flow, Dusty Boundary Layer, Fluidized Bed.

Subject Categories:

  • Nuclear Weapons
  • Fluid Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE