Modeling Enhanced Energy Release in Turbulent Exothermic Flows in Closed Chambers by an Inverse Meth
Agency / Branch:
DOD / DTRA
Toward understanding how turbulent mixing with air of detonation products of fuel-rich explosives results in further combustion of the detonation products and, therefore, enhanced lethality, we first consider an exothermic reaction of a premixed fuel/oxidizer in a closed vessel in the limit of zero Mach number and infinite Reynolds, Peclet, and Damkohler numbers. To help elucidate the main mechanisms that govern turbulent exothermic flows, the problem is modeled using the ""inverse"" problem approach of Oppenheim and Kuhl, which utilizes some performance test data. Accordingly, the flow field associated with the reaction is an incompressible, inviscid flow consisting of two regions of unequal density separated by a thin front where the exothermic reaction takes place. The specific volumes for each region as well as the thermodynamic pressure acting uniformly in both are assumed functions of time only and are determined using a thermodynamic analysis bases on global mass, volume, and energy balances. The present proposal addresses the problem of computing the incompressible flow and the exothermic front, which are consistent with the global thermodynamic analysis. For this purpose, we will adapt the generalized hydrodynamic approach of Rogers to the present problem. numerical methods based on this approach have successfully treated incompressible flow with pathological free surface phenomena such as breaking and splashing of waves, plume formation, collapse of underwater bubbles, and others. A unique feature of our method is that the front will be captured automatically as the solution evolves without special methods or logic for explicitly determining its location. enhanced energy release from internal blasts in underground bunkers or ship compartments due to afterburning of warhead's detonation products in air provides increased lethality. Predictive capability can also provide better estimates of blast effects from terrorist activity or accidental detonation or deflagration of stored munitions, and better design of piston engines.
Small Business Information at Submission:
Principal Investigator:Jay M. Solomon
Enig Associates, Inc.
11120 New Hampshire Ave., Suite 500 Silver Spring, MD 20904
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