Dynamic mode decomposition of trip-induced hypersonic boundary layer transition

Prakash Shrestha, Joseph W. Nichols, Graham V. Candler, Mihailo R. Jovanović

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

Abstract

We study the transition of a Mach 5.65 laminar boundary layer tripped by an array of diamond shaped roughness elements using large-scale direct numerical simulations. A low Reynolds number experiment conducted at the Actively Controlled Expansion Hypersonic Wind Tunnel, Texas A & M University National Aerothermochemistry Laboratory is used to validate our simulation. Planar acoustic disturbances are applied at the in flow boundary to mimic the wind tunnel ambient environment. To accurately capture flow physics, a high- order, low-dissipation scheme for the convection terms in the Navier-Stokes equations is used. Visualizations and statistics of the flow explore the dominant and dynamically significant flow structures : the upstream vortex system, the shock system, and the downstream separated shear layer/wake region which originates from the top and sides of the roughness elements. Three-dimensional snapshots of pressure were considered to select dominant dynamic mode decomposition modes using Chu's disturbance energy norm. A coupled system at 30 kHz consisting of the shock system, the separated shear layer/wake region and the upstream vortex system is determined to have the most disturbance energy. The origin of disturbances is observed to be the upstream vortex system while the wake region acts as a dominant amplifier. Comparison of the flow structures and modes of transition between an isolated cylindrical roughness element and the array of diamond shaped roughness elements is performed.

Original languageEnglish (US)
Title of host publication47th AIAA Fluid Dynamics Conference, 2017
PublisherAmerican Institute of Aeronautics and Astronautics Inc, AIAA
ISBN (Print)9781624105005
StatePublished - Jan 1 2017
Event47th AIAA Fluid Dynamics Conference, 2017 - Denver, United States
Duration: Jun 5 2017Jun 9 2017

Publication series

Name47th AIAA Fluid Dynamics Conference, 2017

Other

Other47th AIAA Fluid Dynamics Conference, 2017
CountryUnited States
CityDenver
Period6/5/176/9/17

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  • Cite this

    Shrestha, P., Nichols, J. W., Candler, G. V., & Jovanović, M. R. (2017). Dynamic mode decomposition of trip-induced hypersonic boundary layer transition. In 47th AIAA Fluid Dynamics Conference, 2017 (47th AIAA Fluid Dynamics Conference, 2017). American Institute of Aeronautics and Astronautics Inc, AIAA.