Transient growth in oblique shock wave/laminar boundary layer interactions at mach 5.92

Nathaniel Hildebrand, Joseph W Nichols, Graham V Candler, Mihailo R. Jovanović

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

1 Scopus citations

Abstract

We investigate the nonmodal physical mechanisms responsible for transient growth in a hypersonic laminar boundary layer and in the interaction of this boundary layer with an incident oblique shock wave. The optimal disturbances and growth curves are computed using an adjoint looping approach. We validate this iterative approach by applying it to several parallel boundary layers that have been studied before in great detail. For these parallel flows, the lift-up effect is generally the dominant transient growth mechanism. However, for a Mach 5.92 spatially developing boundary layer, the inviscid Orr mechanism and convective instabilities are responsible for the large transient response. Furthermore, the optimal initial condition corresponding to the oblique shock wave/boundary layer interaction could be related to both the inviscid Orr mechanism and the lift-up effect. Tilted streamwise streaks that oppose the mean shear are present in the upstream boundary layer, and centrifugal instability near the apex of the separation bubble creates small vortices that grow into elongated streamwise structures with time. Due to the strong spatial non-normality of the oblique shock wave/boundary layer interaction, one cannot obtain an accurate lower bound of the transient growth using the direct or adjoint information separately. Therefore, the nonmodal technique, which takes advantage of both the direct and adjoint operators, is an elegant solution to this problem.

Original languageEnglish (US)
Title of host publication2018 Fluid Dynamics Conference
PublisherAmerican Institute of Aeronautics and Astronautics Inc, AIAA
ISBN (Print)9781624105531
DOIs
StatePublished - Jan 1 2018
Event48th AIAA Fluid Dynamics Conference, 2018 - Atlanta, United States
Duration: Jun 25 2018Jun 29 2018

Publication series

Name2018 Fluid Dynamics Conference

Other

Other48th AIAA Fluid Dynamics Conference, 2018
CountryUnited States
CityAtlanta
Period6/25/186/29/18

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  • Cite this

    Hildebrand, N., Nichols, J. W., Candler, G. V., & Jovanović, M. R. (2018). Transient growth in oblique shock wave/laminar boundary layer interactions at mach 5.92. In 2018 Fluid Dynamics Conference [AIAA 2018-3221] (2018 Fluid Dynamics Conference). American Institute of Aeronautics and Astronautics Inc, AIAA. https://doi.org/10.2514/6.2018-3221