Publications

Investigation of mixing law efficacy for gaseous hydrodynamic simulations

White, Caleb D.; Silva, Humberto; Vorobieff, Peter

A computational simulation of various mixing laws for gaseous equations of state using planar traveling shocks for multiple mixtures in three dimensions is analyzed against nominal experimental data. Numerical simulations use the Sandia National Laboratories shock hydrodynamic code CTH and other codes including the thermochemical equilibrium code TIGER and the uncertainty qualification and sensitivity analysis code DAKOTA. The mixtures are 1:1 and a 1:3 molar mixtures of helium and sulfur hexafluoride. The mixing laws to be analyzed are the ideal-gas law, Amagat’s law, Dalton’s law, the Becker–Kistiakowsky–Wilson equation of state (EOS), the exponential 6 EOS, and the Jacobs-Cowperthwaite-Zwisler EOS. Examination of the experimental data with TIGER revealed that the shock strength should not be strong enough to turn the mixture nonideal because the compressibility factor z was essentially unity (z ≈ 1.02). Experimental results show that none of the equations of state are able to accurately predict the properties of the shocked mixture; similar discrepancies have been observed in previous works. Kinetic molecular theory appears to introduce a parameter that offers an explanation regarding the discrepancies. Implementation of the kinetic molecular theory parameter into the EOS is left for future work.