Turbulent dusty boundary layer in an ANFO surface-burst explosion
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 in 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 will 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. The chaotic flow was averaged along similarity lines (i.e., lines of constant values of x = r/Rs and y = z/Rs where R{sub s} = ct{sup {alpha}}) to establish the mean-flow profiles and the r.m.s. fluctuating-flow profiles of the boundary layer.
- Research Organization:
- Lawrence Livermore National Lab., CA (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 10140648
- Report Number(s):
- UCRL-JC-108985; CONF-920707-28; ON: DE92012101
- Resource Relation:
- Conference: 24. international symposium on combustion,Sydney (Australia),5-10 Jul 1992; Other Information: PBD: Jan 1992
- Country of Publication:
- United States
- Language:
- English
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