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Shock tube
About: Shock tube is a research topic. Over the lifetime, 6963 publications have been published within this topic receiving 99372 citations.
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TL;DR: In this paper, an electric arc-driven shock tube operating as a reflected shock tunnel produces stagnation conditions of 5600 K and 100 atm in a two-dimensional nozzle flow with spontaneous Raman scattering and the experimental results are compared with two theoretical models: (1) the Landau-Teller relaxation model and (2) a numerical solution of the master equations using transition rates derived from Schwartz, Slawsky and Herzfeld (SSH) theory.
Abstract: Vibrational relaxation of nitrogen in a two-dimensional nozzle flow is studied with spontaneous Raman scattering. An electric arc-driven shock tube operating as a reflected shock tunnel produces stagnation conditions of 5600 K and 100 atm. A 248-nm KrF laser pulse is focused into the nozzle to produce spatially resolved spontaneous Raman spectra. Vibrational population distributions are derived from the spectra for the states v = 0 to v = 8. The experimental results are compared with two theoretical models: (1) the Landau-Teller relaxation model and (2) a numerical solution of the master equations using transition rates derived from Schwartz, Slawsky and Herzfeld (SSH) theory. We have measured a value for the Landau-Teller correction factor (phi) to be 1.0-1.5. 13 refs.
51 citations
TL;DR: In this paper, the rates of vibrational relaxation of N2 by H2O and the vibrational exchange between N2 and CO were measured in mixtures of 1%−10% CO+∼1% H2+N2.
Abstract: Shock tube measurements of the rates of vibrational relaxation of N2 by H2O and the vibrational exchange between N2 and CO are described. Simultaneous measurements of H2O v2 ν2 band and CO fundamental band ir emission were performed in mixtures of 1%–10% CO+∼1% H2O+N2. Measurement of H2O emission by a calibrated optical system allowed an accurate determination of the concentration of H2O for each run. The CO emission had two, almost decoupled, regions of behavior which allowed determination of two relaxation times: Pτ NCe≈ 1.6 atm· μsec (V–V exchange relaxation time between N2 and CO) and Pτ NH≈ 1.5 atm· μsec (T–V relaxation of N2 by H2O), both for 960 〈T〈2200°K.
51 citations
TL;DR: In this article, a series of experiments were conducted to study the influence of a cloud of water droplets on the propagation of a planar shock wave in a vertically oriented shock tube, where the cloud of droplets was released downwards into the air at atmospheric pressure while the shock wave propagated upwards.
Abstract: We conducted a series of shock tube experiments to study the influence of a cloud of water droplets on the propagation of a planar shock wave. In a vertically oriented shock tube, the cloud of droplets was released downwards into the air at atmospheric pressure while the shock wave propagated upwards. Two shock wave Mach numbers, 1.3 and 1.5, and three different heights of clouds, 150 mm, 400 mm, and 700 mm, were tested with an air-water volume fraction and a droplet diameter fixed at 1.2% and 500 mu m, respectively. From high-speed visualization and pressure measurements, we analyzed the effect of water clouds on the propagation of the shock wave. It was shown that the pressure histories recorded in the two-phase gas-liquid mixture are different from those previously obtained in the gas-solid case. This different behavior is attributed to the process of atomization of the droplets, which is absent in the gas-solid medium. Finally, it was observed that the shock wave attenuation was dependent on the exchange surface crossed by the shock combined with the breakup criterion. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3657083]
51 citations
51 citations
10 Jul 1995
51 citations