Comparison of Measured and Predicted Conditions behind a Reflected Shock

• Published in: The Physics of fluids (1958) 1970-02, Vol.13 (2), p.372-377
• Main Authors: Bengtson, Roger D., Miller, Myron H., Koopman, David W., Wilkerson, T. D.
• Format: Article
• Language: English
• ISSN: 0031-9171; 2163-4998
• DOI: 10.1063/1.1692928

Measured thermodynamic conditions behind reflected shocks in a gas‐driven diaphragm shock tube are compared to Rankine‐Hugoniot predictions. Pressures of the shock‐heated neon, which contained small concentrations of spectroscopic additives, were measured by quartz transducers. Temperatures (9000‐13 000°K) were simultaneously measured spectroscopically by line reversal and absolute emission techniques, while electron densities were measured by the broadening of the Balmer line H β . The temperature has been measured to an accuracy of ±1.5%, while electron densities have been determined with an accuracy of ±10%. Pressure measurements attained accuracies of ±5%. The consistency of the data indicates that a homogeneous local thermodynamic equilibrium model is an adequate description of the shock‐heated gas. The state measurements, compared with the real gas Rankine‐Hugoniot predictions, show significant departures. Predicted temperatures are typically 3% ± 10% higher than those measured. The predicted electron density is as much as ±30% in error, and the predicted pressures are systematically lower than those measured by approximately 7% ± 15%.