Effect of sweep on the mean and unsteady structures of impinging shock/boundary layer interactions

Adam C. Doehrmann, Sathyan Padmanabhan, James A.S. Threadgill, Jesse C Little

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

5 Scopus citations


An experimental investigation has been conducted to assess the effect of sweep on impinging oblique Shock/Boundary Layer Interactions (SBLIs), specifically focused on the distribution of mean and fluctuating pressure signatures at the wall. Four shock generators are utilized with x-y plane deflection of θ = 12.5, and x-z plane sweep angles of 15.0, 22.5, 30.0, and 40.0. The induced swept oblique shocks impinge upon the naturally turbulent Mach 2.3 boundary layer along the tunnel floor (Reθ ≈ 5000). The resultant SBLIs all exhibit significant separation, with a structure that grows in the spanwise direction. Flow features are assessed using oil-flow visualization, static pressure tapings, and fast-response pressure transducers. The rise in mean pressure near separation scales locally with cylindrical similarity suggesting the three-dimensional separation along the span obeys Free Interaction Theory. Local reattachment behavior is only mildly dependent upon span, yet the overall shock structure is clearly conical. Low-frequency unsteadiness is observed beneath the separation shock foot in all cases, shifting towards higher frequencies as sweep is increased. Spanwise ripples in the separation shock attributed to the low-frequency wall-pressure signature travel along the shock span with velocities an order of magnitude below that of the freestream flow. Results offer a vital insight into characterizing swept SBLI behavior in a fundamental configuration that has been largely overlooked in literature.

Original languageEnglish (US)
Title of host publicationAIAA Aerospace Sciences Meeting
PublisherAmerican Institute of Aeronautics and Astronautics Inc, AIAA
ISBN (Print)9781624105241
Publication statusPublished - Jan 1 2018
EventAIAA Aerospace Sciences Meeting, 2018 - Kissimmee, United States
Duration: Jan 8 2018Jan 12 2018


OtherAIAA Aerospace Sciences Meeting, 2018
CountryUnited States


ASJC Scopus subject areas

  • Aerospace Engineering

Cite this

Doehrmann, A. C., Padmanabhan, S., Threadgill, J. A. S., & Little, J. C. (2018). Effect of sweep on the mean and unsteady structures of impinging shock/boundary layer interactions. In AIAA Aerospace Sciences Meeting (210059 ed.). American Institute of Aeronautics and Astronautics Inc, AIAA. https://doi.org/10.2514/6.2018-2074