Modal Analysis of Instabilities in the BoLT-2 Flowfield

Zachary M Johnston, Maziar S. Hemati, Graham V. Candler

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


Boundary layer disturbances in the Boundary Layer Turbulence (BoLT-2) flowfield are investigated using a combination of low-dissipation numerics and a novel shock capturing scheme. This allows us to investigate the later stages of the transition process governed by nonlinear evolution of the boundary layer state. Unsteady simulations using US3D are performed with broadband stochastic forcing to mimic quiet wind tunnel noise. Disturbances are introduced at an interpolated inflow plane located downstream of the leading edge to allow disturbances to grow which are induced by boundary layer instability mechanisms. Two-dimensional time series snapshots are collected at streamwise locations along the geometry to compute spatio-temporal information from extracted boundary layer modes. Modal analysis is performed with a streaming version of total dynamic mode decomposition (STDMD) with a compressible energy norm weighting to identify modes associated with distinct transition processes. Frequencies computed from STDMD modes show excellent agreement with power spectral density peaks measured from experiments and simulation.

Original languageEnglish (US)
Title of host publicationAIAA SciTech Forum 2022
PublisherAmerican Institute of Aeronautics and Astronautics Inc, AIAA
ISBN (Print)9781624106316
StatePublished - 2022
EventAIAA Science and Technology Forum and Exposition, AIAA SciTech Forum 2022 - San Diego, United States
Duration: Jan 3 2022Jan 7 2022

Publication series

NameAIAA Science and Technology Forum and Exposition, AIAA SciTech Forum 2022


ConferenceAIAA Science and Technology Forum and Exposition, AIAA SciTech Forum 2022
Country/TerritoryUnited States
CitySan Diego

Bibliographical note

Funding Information:
This work was supported by the DoD HPCMP Hypersonic Vehicle Simulation Institute, the Collaborative Center for Aerospace Sciences, and the Air Force Office of Scientific Research (AFOSR) under award number FA9550-21-1-0106. The views and conclusions contained herein are those of the authors and should not be interpreted as necessarily representing the official policies or endorsements, either expressed or implied, of the AFOSR or the U.S Government. Also, the authors would like to thank Heather Kostak for sharing experimental findings and providing experimental data obtained in the Mach 6 Quiet Tunnel at Texas A&M University.

Publisher Copyright:
© 2022, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved.


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