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


Personal Author(s) : Kuhl, Allen L ; Ferguson, R E ; Chen, K -Y ; Collins, J P


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a254130.pdf


Report Date : 01 Aug 1992


Pagination or Media Count : 52


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.


Descriptors :   *SURFACE BURST , *TURBULENT BOUNDARY LAYER , *EXPLOSION EFFECTS , *DUST , TEST AND EVALUATION , VELOCITY , MATHEMATICAL MODELS , NUCLEAR EXPLOSIONS , SIMULATION , DENSITY , DIAMETERS , MODELS , INTERACTIONS , SHOCK , SCALE , STRUCTURAL RESPONSE , BOUNDARIES , SURFACES , MIXTURES , RUPTURE , TURBULENT FLOW , BOUNDARY LAYER , FLUIDIZED BED PROCESSES , DETONATIONS , ENTRAINMENT , BLAST , MIXING , AIR , LAYERS , SHOCK WAVES , STRUCTURES , FIELD TESTS , BLAST WAVES , EXPLOSIONS


Subject Categories : Nuclear Weapons
      Fluid Mechanics


Distribution Statement : APPROVED FOR PUBLIC RELEASE