Modeling Deflagration in Energetic Materials using the Uintah Computational Framework

Abstract

Predictive computer simulations of highly resolved large-scale 3D deflagrations and detonations are dependent on a robust reaction model embedded in a computational framework capable of running on massively parallel computer architectures. We have been developing such a model in the Uintah Computational Framework, which has exhibited good strong and weak scaling characteristics up to 512K cores [16]. Our focus is on predicting a Deflagration to Detonation Transition (DDT) when a large number of energetic devices are present. An example of this is a semi-tractor-trailer loaded with thousands of mining boosters that rolled over, ignited and went through a DDT. Our current reaction model adapts components from a) Ward, Son and Brewster[22] which incorporates the effects of pressure and initial temperature on deflagration, b) Berghout et al.[9] to model burning in cracks of damaged explosives, and c) Souers[20] for describing fully developed detonation. The reaction model has been subjected to extensive validation against experimental tests. Current efforts are focused on the effects of varying the grid resolution on multiple aspects of deflagration and the transition to detonation.

Packing Configurations of PBX‐9501 Cylinders to Reduce the Probability of a Deflagration to Detonation Transition (DDT)

“…gaseousp roducts at multiple initial temperatures andp ressures [17,18,19,20].T he DDT modelu tilizes am odified Ward, Son, and Brewster (WSB) burn model [18,20,21] to evaluate the mass conversion rate, the ViscoSCRAM constitutive model [22] to model the damage in the solid, and the JWL ++ simple reactive flow model [23] to describe detonation.T he commonly used JWL equation of state [ 23,24] was used for the solid explosivea nd the product gases. Detonation occurs in Uintah's DDT model whent he localized pressure is greater than the pressure threshold, 5.3 GPa [17,18].F urther details on the model can be found in references [ 17,18,19,20,25].T he Uintah framework has al ong history of high performance computing and has shown goods trong and weak scaling characteristics up to 512 Kc ores on DOE's Mira [26,27,28].U intah's strong scalability enabled us to run large 2D and full 3D simulations at high grid resolutions (2 mm). The reactionm odel has been validated at many resolutions including 2mm [ 19,29].…”

Experimental and Simulation Study on the Ignition Criterion of JHL‐3 under Non‐Shock Loading

“…The ignition temperature was obtained based on the temperature history curve measured by the thermocouple sensor in experiments. The threshold pressure means that for a cell to be ignited after conduction combustion has been started, the product gas pressure in a surrounding cell must be above this critical pressure for convective deflagration [39].…”

Extending the Uintah Framework through the Petascale Modeling of Detonation in Arrays of High Explosive Devices

“…These are simply the mean values of the donor material (PBX-9501) in the volume. The model for the mass conversion or mass burn rate is discussed below with full details provided in [4].…”

“…where T 0 is the initial bulk solid temperature, κ is the thermal conductivity, E is the activation energy, R is the ideal gas constant C P is the specific heat, Q is the heat released and x r , x s are physical lengths [4].T s is a sub-scale surface temperature, not to be confused with T r or T s in Eqs. (3.4, 3.5, 3.8, 3.10).…”