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Shock tubes are used to investigate the chemical kinetics and radiative properties of gasses. Analyses of the flow conditions produced in shock tubes typically assume a single, constant shock speed...

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.

An axisymmetric viscous shock tube simulation code is developed that keeps the shock and the contact discontinuity stationary in suitably constructed moving frames of reference. The flowfield aroun...

Shock tube experiments are a cornerstone of investigations into the hypersonic flight environment. However, the actual flow through the basic shock tube has not been well characterized in the literature, and nonuniformities arising in the test gases are not well understood. This work produces a quasi-one-dimensional analytical methodology for predicting the nonuniformities in the postshock test gas based exclusively on the experimentally measured history of shock speed down the tube. Wave effects extracted from shock speed variations are shown to provide all information necessary in order to reconstruct the test slug from any particular experiment. Accurate representation of flow dynamics is initially checked against argon test cases following accelerating and decelerating shock trajectories, each with a tube-end Mach number of 6.5 and a fill pressure of 66.66 Pa in a tube of 100 mm diameter. Agreement between the method and results from a viscous, axisymmetric Navier–Stokes solution is found to be within 1% in pressure and temperature.

The flow physics modeling and validation of the Royal Aircraft Establishment (RAE) subsonic intake Model 2129 (M2129) are presented. This intake has an 18 inches long S duct with a 5.4 inches offset, an external and an internal lip, forward and rear extended ducts, and a center-positioned bullet before the outlet. Steady-state and unsteady experimental data are available for this duct. The measurements include engine face conditions (pressure recovery, static pressure to free-stream total pressure ratio, and distortion coefficient at the worst 60 ∘ sector or DC60), as well as wall static pressure data along the duct. The intake has been modeled with HPCMP CREATE TM -AV Kestrel simulation tools. The validation results are presented including the effects of turbulence models on predictions. In general, very good agreement (difference errors are less than 6%) was found between predictions and measurements. Secondary flow at the first bend and a region of flow separation are predicted at the starboard wall with an averaged DC60 coefficient of 0.2945 at the engine face. Next, a passive and an active flow control method are computationally investigated. The passive one uses vane-type vortex generators and the active one has synthetic jet actuators. The results show that considered passive and active flow control methods reduce the distortion coefficient at the engine face and the worst 60 ∘ sector to 0.1361 and 0.0881, respectively. The flow control performance trends agree with those obtained in experiments as well. These results give confidence to apply the Kestrel simulation tools for the intake design studies of new and unconventional vehicles and hence to reduce the uncertainties during their flight testing.