On Unsteady Shock Wave Reflection from a Concave Cylindrical Surface
The paper is devoted to a combined—analytical, numerical, and experimental—study of initially planar shock reflection from a full concave cylindrical surface with the emphasis on the transition from inverse Mach reflection to transitioned regular reflection. The numerically predicted and experimentally observed transition angles for a range of incident shock Mach numbers are found to be in good agreement with each other and at the same time significantly different from previous experimental observations in the literature. It is shown that among existing analytical predictions of the transition point location, the theory by Itoh et al. (JFM 108:383–400) provides the best agreement with new experimental and numerical data, even though this theory is in significant error with respect to the triple-point trajectory and Mach stem intensity. By tracking the corner signal, it is shown that it remains attached to the Mach stem during the entire course of flow development and, hence, effectively propagates with the Mach stem velocity. This finding is used for the initial development of another analytical treatment to predict the location of the transition point.
The present research is supported by the Fonds de recherche du Quèbec - Nature et technologies (FRQNT) via the Team Research Project program and the National Science and Engineering Research Council (NSERC) via the Discovery Grant program. F.A.P. gratefully acknowledges the McGill Engineering Undergraduate Student Masters Award (MEUSMA) funded in part by the Faculty of Engineering, McGill University. Rabi Tahir’s support regarding Masterix code is greatly appreciated.
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