Study of real gas effects by using a Mach 20 hypersonic shock tube

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In simulating experimentally atmospheric re-entry of space vehicles, shock wave technology is best used to create high temperature conditions which are otherwise impossible to generate by any together methods. The high temperature so far appearing during the atmospheric re-entry exceed 10,000 K so that air molecules will dissociate and then ionized. This process is name real gas effect. The present study aims to experimentally verify the hypersonic real gas effect by using a 100 mm x 180 mm hypervelocity shock tube that has been transported from the Institute of Aerospace Studies, University of Toronto in 1994. The present study is to refurbish this shock tube by adopting a detonation driver system in which the reflection of detonation waves in stoichiometric oxyhydrogm mixture is used and to quantitatively visualize hypersonic shock waves using double exposure holography interferometry.The result obtained are summarized as following :(1) A diaphragmless operation system has been adopted successfully in this shock tube. Its characteristics have been throughly investigated. Its higher degree of repeatability that has not been achieved among existing shock tubes has been confirmed.(2) To ensure the initiation of detonations in the high pressure chamber, the transition from deflagration driven shock waves to detonation waves has been visualized using double exposure holographic interferometry. The effect of small particles shattering from the surface of micro-charges which initiate the chemical reaction.(3) Finite fringe holographic interferometry has been applied to the experiments in (2). Finite fringe interferograms were quantitatively analyzed by using Fourier fringe analysis. Its measuring system has been established.(4) Results obtained during two years of research works have been presented at international symposia. International collaboration with the Institute of Aerospace Studies, University of Toronto has been conducted.