The vortical, acoustic and thermal components of global eigenfunctions of supersonic jets

Michael Karp, M. J. Philipp Hack

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

Abstract

The effect of the nozzle on the instability mechanism of fully expanded supersonic jets is assessed by means of global stability analysis. Two setups are considered: a jet emanating from a convergent nozzle and an additional setup, where the nozzle is replaced by a parallel jet, which allows us to isolate the effect of the nozzle wall on the instability mechanism. Both setups are found to be globally unstable, indicating of absolute instability. It is concluded that the flow is absolutely unstable due to the presence of a sharp streamwise gradient in the base flow and the role of the nozzle is limited to the generation of this gradient. Inclusion of the nozzle walls leads to a reduction of the instability growth rate due to its constraining effect. The vortical, acoustic and thermal components of the eigenfunctions are analyzed using the momentum potential theory by Doak1 .

Original languageEnglish
Title of host publicationAIAA Scitech 2021 Forum
Pages1-11
Number of pages11
StatePublished - 2021
Externally publishedYes
EventAIAA Science and Technology Forum and Exposition, AIAA SciTech Forum 2021 - Virtual, Online
Duration: 11 Jan 202115 Jan 2021

Publication series

NameAIAA Scitech 2021 Forum

Conference

ConferenceAIAA Science and Technology Forum and Exposition, AIAA SciTech Forum 2021
CityVirtual, Online
Period11/01/2115/01/21

All Science Journal Classification (ASJC) codes

  • Aerospace Engineering

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