Direct numerical simulations of nonlinear entropy-layer instability waves

John A. Meersman, Christoph Hader, Hermann F. Fasel

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

Abstract

Direct Numerical Simulations (DNS) were carried out for a blunted straight cone geometry at Mach 6 in order to investigate the nonlinear stages of the transition process initiated by disturbances in the entropy layer. The flow conditions of the Boeing/AFOSR Mach 6 Quiet Tunnel (BAM6QT) at Purdue University were used for the numerical investigations. In the simulations, “controlled” disturbances were introduced locally into the entropy layer by volume forcing of the energy equation. Low amplitude (linear) DNS revealed an unstable region that was not found using conventional Linear Stability Theory (LST), which only found a weak entropy mode instability for two-dimensional waves. A highly-resolved oblique breakdown DNS has shown that transition can be initiated by forcing large amplitude, oblique disturbances in the entropy layer. Streamwise “hot” streaks were observed in Stanton number contours on the surface of the cone. The streak spacing in the azimuthal direction corresponds to the azimuthal wavenumber of the steady streamwise mode that is nonlinearly generated by the forced oblique waves.

Original languageEnglish (US)
Title of host publicationAIAA Scitech 2021 Forum
PublisherAmerican Institute of Aeronautics and Astronautics Inc, AIAA
Pages1-16
Number of pages16
ISBN (Print)9781624106095
StatePublished - 2021
EventAIAA Science and Technology Forum and Exposition, AIAA SciTech Forum 2021 - Virtual, Online
Duration: Jan 11 2021Jan 15 2021

Publication series

NameAIAA Scitech 2021 Forum

Conference

ConferenceAIAA Science and Technology Forum and Exposition, AIAA SciTech Forum 2021
CityVirtual, Online
Period1/11/211/15/21

ASJC Scopus subject areas

  • Aerospace Engineering

Fingerprint

Dive into the research topics of 'Direct numerical simulations of nonlinear entropy-layer instability waves'. Together they form a unique fingerprint.

Cite this