Two dimensional numerical prediction of deflagration-to-detonation transition in porous energetic materials.
This paper describes a two-dimensional code developed for analyzing two-phase deflagration-to-detonation transition (DDT) phenomenon in granular, energetic, solid, explosive ingredients. The two-dimensional model is constructed in full two-phase, and based on a highly coupled system of partial differential equations involving basic flow conservation equations and some constitutive relations borrowed from some one-dimensional studies that appeared in open literature. The whole system is solved using an optimized high-order accurate, explicit, central-difference scheme with selective-filtering/shock capturing (SF-SC) technique, to augment central-diffencing and prevent excessive dispersion. The sources of the equations describing particle-gas interactions in terms of momentum and energy transfers make the equation system quite stiff, and hence its explicit integration difficult. To ease the difficulties, a time-split approach is used allowing higher time steps. In the paper, the physical model for the sources of the equation system is given for a typical explosive, and several numerical calculations are carried out to assess the developed code. Microscale intergranular and/or intragranular effects including pore collapse, sublimation, pyrolysis, etc. are not taken into account for ignition and growth, and a basic temperature switch is applied in calculations to control ignition in the explosive domain. Results for one-dimensional DDT phenomenon are in good agreement with experimental and computational results available in literature. A typical shaped-charge wave-shaper case study is also performed to test the two-dimensional features of the code and it is observed that results are in good agreement with those of commercial software.
Defense Industries Research and Development Institute, Scientific and Technological Research Council of Turkey, Ankara, Turkey. Electronic address: bekir.narin@tubitak.gov.tr.
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Narin
Department of Aerospace Engineering, Middle East Technical University, Ankara, Turkey.
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Ozyörük
Department of Mechanical Engineering, Middle East Technical University, Ankara, Turkey.
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Ulas
D001392:Azocines; D005107:Explosions; D053834:Explosive Agents; D008962:Models, Theoretical; D016062:Porosity
D001392:Azocines; D053834:Explosive Agents; C007950:octogen
Deflagration-to-detonation transition (DDT); Energetic; Microscale effects; Solid explosive ingredients; Temperature switch; Time-split approach