Shock tube

About: Shock tube is a research topic. Over the lifetime, 6963 publications have been published within this topic receiving 99372 citations.

An Analysis of Combustion Studies in Shock Expansion Tunnels and Reflected Shock Tunnels

Abstract: The effect of initial nonequilibrium dissociated air constituents on the combustion of hydrogen in high-speed flows for a simulated Mach 17 flight condition was investigated by analyzing the results of comparative combustion experiments performed in a reflected shock tunnel test gas and in a shock expansion tunnel test gas. The results were analyzed and interpreted with a one-dimensional quasi-three-stream combustor code that includes finite rate combustion chemistry. The results of this study indicate that the combustion process is kinetically controlled in the experiments in both tunnels and that the presence of the nonequilibrium partially dissociated oxygen in the reflected shock tunnel enhances the combustion. Methods of compensating for the effect of dissociated oxygen are discussed.

Rate constants for the reaction O+D2→OD+D by the flash photolysis–shock tube technique over the temperature range 825–2487 K: The H2 to D2 isotope effect

Abstract: Rate constants for the reaction of O(3P) atoms with deuterium, O+D2→OD+D, have been measured over the temperature range 825–2487 K. The experimental method that has been used is the flash photolysis–shock tube (FPST) technique. This technique utilizes atomic resonance absorption spectroscopy (ARAS) to monitor O‐atom depletion in the presence of a large excess of reactant, D2. The measurement is made in the stagnant reflected shock wave region. Thus, shock heating simply serves to prepare the gas density and temperature for a flash photolytically induced absorption photometric experiment. The results that have been obtained between 825 and 2487 K can be represented by the Arrhenius expression: k=(3.22±0.25)×10−10 exp(−7293±98 K/T) cm3 molecule−1 s−1. The average deviation of the present data from this equation is ±17%. An alternative three parameter expression that represents the data to within ±16% is k=1.95×10−15 T1.45 exp(−5250 K/T) cm3 molecule−1 s−1. When the recent results of Zhu, Arepalli, and Gordo...

Studies with a Single‐Pulse Shock Tube. I. The Cis—Trans Isomerization of Butene‐2

Abstract: The cis—trans isomerization of butene‐2 was investigated behind reflected shocks in a single‐pulse shock tube of a novel design. The temperature range covered was 1000°—1250°K, and concentrations of 1% and 6% of the butene in argon were used. Analyses were made by vapor‐phase chromatography. The first‐order rate constants obtained in this work fall slightly above the extrapolated Arrhenius curves of two recent low‐temperature studies. An activation energy of 65, rather than 62.8 kcal/mole, is obtained when a straight line is drawn between the high and the low temperature data. |The rate constant obtained is kcis∞=3.5×1014exp(−65×103/RT). Possible sources of errors in evaluating reaction times in the single‐pulse shock tube are discussed.

Aerodynamic Separation Effect on Gas and Isotope Mixtures Induced by Invasion of the Free Jet Shock Wave Structure

Abstract: The shock wave system of the underexpanded free jet, in a region where the pressure is in the range of 10−2 up to 1 torr, is partly invaded by background molecules, these latter being pumped and carried by the supersonic flow. When a gas mixture is introduced into the nozzle chamber and outside the shock barrel, this aspiration acts very selectively on the light molecules, and a mixture enriched in lighter species is attainable by skimming the free jet. This new aerodynamic separation effect, which is applicable to isotopic mixtures, is very strong in comparison to the efficiency of an elementary gaseous diffusion membrane.