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Current investigations of energetic structural materials involve shock-induced and shock-assisted chemical reactions in which complex physical processes are only elucidated by computational models of gas gun experiments at the present time. Physics models that describe the equation of state, material strength, heat transfer, and chemical reaction for energetic structural materials must be calibrated with experimental data to obtain material constants. Numerical solutions introduce errors that are difficult to quantify. This paper introduces a verification procedure of a code appropriate for simulation of gas gun experiments with energetic structural materials. Simulated gas gun experiments involving the Ni + Al mixture are used to illustrate the proposed verification procedure. The physics models together with the conservations of mass, momentum, and energy are explicitly solved using a second order finite volume scheme.

Current investigations of energetic structural materials involve shock-induced and shock-assisted chemical reactions in which complex physical processes are currently only elucidated by computational models of gas-gun experiments. The equation of state is one of the most important parts of the constitutive models incorporated into models that describe the processes in shock-induced and shock-assisted chemical reactions. Implementation of current methods typically requires simplifying assumptions in the mixture rules. In this paper, two new equation-of-state methods are proposed that 1) are used to physically interpret both homobaric and uniform-strain assumptions, 2) do not require mixture-averaged equation-of-state model parameters, and 3) do not have any restrictions on the form of constituent equation-of-state or pore-collapse model. The proposed methods are compared with other mixture equation-of-state methods, and cases in which the mixture is porous are demonstrated. Gas-gun experiments are simulated and compared with experimental data for a material with 2Al, [Fe.sub.2][O.sub.3], 20 wt % Epon 828, and voids, in which the reaction initiation threshold was not reached. The simulation integrates conservation equations and momentum balance using a second-order finite volume scheme. DOI: 10.2514/1.34472