| Summary: | Shock tube experiments are a primary means of obtaining ground test data for the hypersonic regime. Accurate characterization of the test gas is crucial to understanding experimental results. However, characterization of the flows produced behind the shock wave has historically proven challenging. This paper applies a methodology to calculate the shocked test gas properties using the experimentally recovered shock speed profile. Static pressure, pitot pressure, and heat transfer predictions are found to closely match the experimental data for a range of shock trajectories with both argon and air test gases. Thermochemical variations in the test gases are found to depend strongly on variations in shock speed along the tube. It is shown that characterization of the test gases requires accommodating the influence of wave effects associated with the varying shock speed. Tube diameter is found to influence test time significantly in interaction with a variable shock speed, and also the magnitude of nonuniformities in the test gas. Location and number of shock timing stations in experimental facilities are found to play a vital role in the ability to accurately characterize the test gas of a given experiment.
|
|---|