Detonation Product Equation of State Determination from the Slab Expansion Test via an Analytic Methodology

Combustion is often used to generate high pressure gaseous products have the potential to do work on adjacent solid confining materials. The product gas equation of state governs the transfer of energy from the energy-dense products to the confiner. Detonation of condensed phase explosives can generate product pressures exceeding 40 GPa with temperatures estimated to exceed 3000 K. Direct measurement of the equation of state at these conditions can be challenging. Conventional pressure transducers cannot function at these extreme conditions. Instead, the EOS can be inferred from measuring motion of the solid confiner. The acceleration history yields the pressure, while the position informs the informs volume. Traditionally this measurement has been performed using an axisymmetric cylindrical confiner geometry, but there has been recent interest in a two-dimensional rectangular slab geometry. In this work, an analytic methodology is presented to extract the equation of state of the driving gas from the motion history of the slab-shaped confiner. The method is applied to experimental data and compared to numerical calculations.