Transition delay in hypervelocity boundary layers by means of CO 2/acoustic instability interactions

Ivett A. Leyva, Stuart Laurence, Amy War Kei Beierholm, Hans G. Hornung, Ross Wagnild, Graham V Candler

Research output: Chapter in Book/Report/Conference proceedingConference contribution

31 Scopus citations

Abstract

A novel method to delay transition in hypervelocity flows over slender bodies by injecting CO2into the boundary layer of interest is investigated. The results presented here consist of both experimental and computational data. The experimental data was obtained at Caltech's T5 reflected shock tunnel, while the computational data was obtained at the University of Minnesota. The experimental model was a 5 degree sharp cone, chosen because of its relevance to axisymmetric hypersonic vehicle designs and the wealth of experimental and numerical data available for this geometry. The model was instrumented with thermocouples, providing heat transfer measurements from which transition locations were determined and the efficacy of adding CO2 in delaying transition was gauged. For CO2/N2 freestream blends without injection, the transition Reynolds number more than doubled for mixtures with 40% CO2 mole fraction compared to the case of 100% N2. For the cases with injection, shadowgraph visualizations were obtained, allowing verification of the injection timing. The computations provide encouraging results that for the injection schemes proposed CO 2 is reaching high enough temperatures to excite vibrational modes and thus delay transition.

Original languageEnglish (US)
Title of host publication47th AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition
StatePublished - Dec 1 2009
Event47th AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition - Orlando, FL, United States
Duration: Jan 5 2009Jan 8 2009

Other

Other47th AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition
CountryUnited States
CityOrlando, FL
Period1/5/091/8/09

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