Validation of Dalton's and Amagat's laws for gas mixtures with shock propagation*

Dalton’s and Amagat’s laws are known as the law of partial pressures and the law of partial volumes, respectively. These well-known thermodynamic models are used to characterize the properties of gas mixtures. We conducted experiments to assess the accuracy of these laws in predicting the properties of gas mixtures with shock propagation. We present results for two gas mixtures of sulfur hexafluoride (SF₆) and helium (He), with 50%/50% and 25%/75%  SF₆/He molar concentrations. Fast response pressure transducers are used to determine the pressure of each gas mixture both before and after the passage of the shock wave. Temperature readings are obtained using an ultra-fast response mercury cadmium telluride (MCT) infrared (IR) detector, with a response time on the order of 60 nanoseconds. Coupled with a stabilized broadband infrared light source (operating at 1500 K) the MCT detector provides pre- and post-shock line-of-sight readings of average temperature within the shock tube. These experimental results are compared with theoretical to determine if one of the thermodynamic models produces better agreement with experiment.