Sökning: id:"swepub:oai:DiVA.org:kth-328170" >
Large-eddy simulati...
Large-eddy simulations of flow and aeroacoustics of twin square jets including turbulence tripping
-
- Ahn, MyeongHwan (författare)
- KTH,Teknisk mekanik,Linné Flow Center, FLOW
-
- Mihaescu, Mihai, Professor, 1976- (författare)
- KTH,Linné Flow Center, FLOW,Strömningsmekanik och Teknisk Akustik
-
- Karnam, Aatresh (författare)
- University of Cincinnati
-
visa fler...
-
- Gutmark, Ephraim (författare)
- Aerospace Engineering, University of Cincinnati
-
visa färre...
-
(creator_code:org_t)
- AIP Publishing, 2023
- 2023
- Engelska.
-
Ingår i: Physics of fluids. - : AIP Publishing. - 1070-6631 .- 1089-7666. ; 35:6
- Relaterad länk:
-
https://doi.org/10.1...
-
visa fler...
-
https://pubs.aip.org...
-
https://kth.diva-por... (primary) (Raw object)
-
https://urn.kb.se/re...
-
https://doi.org/10.1...
-
visa färre...
Abstract
Ämnesord
Stäng
- In this study, we investigate the flow and aeroacoustics of twin square (i.e., aspect ratio of 1.0) jets by implicit large-eddy simulations (LESs) under a nozzle pressure ratio of 3.0 and a temperature ratio of 1.0 conditions. A second-order central scheme coupled with a modified Jameson's artificial dissipation is used to resolve acoustics as well as to capture discontinuous solutions, e.g., shock waves. The flow boundary layer inside of the nozzle is tripped, using a small step in the convergent section of the nozzle. The time-averaged axial velocity and turbulent kinetic energy of LES with boundary layer tripping approaches better to particle image velocimetry experimental data than the LES without turbulence tripping case. A two-point space–time cross-correlation analysis suggests that the twin jets are screeching and are coupled to each other in a symmetrical flapping mode. Intense pressure fluctuations and standing waves are observed between the jets. Spectral proper orthogonal decomposition (SPOD) confirms the determined mode and the relevant wave propagation. The upstream propagating mode associated with the shock-cell structures is confined inside jets. Far-field noise obtained by solving Ffowcs Williams and Hawkings equation is in good agreement with the measured acoustic data. The symmetrical flapping mode of twin jets yields different levels of the screech tone depending on observation planes. The tonalities—the fundamental tone, second and third harmonics—appear clearly in the far-field, showing different contributions at angles corresponding to the directivities revealed by SPOD.
Ämnesord
- TEKNIK OCH TEKNOLOGIER -- Maskinteknik -- Strömningsmekanik och akustik (hsv//swe)
- ENGINEERING AND TECHNOLOGY -- Mechanical Engineering -- Fluid Mechanics and Acoustics (hsv//eng)
- TEKNIK OCH TEKNOLOGIER -- Maskinteknik -- Rymd- och flygteknik (hsv//swe)
- ENGINEERING AND TECHNOLOGY -- Mechanical Engineering -- Aerospace Engineering (hsv//eng)
Nyckelord
- Large-eddy simulations; supersonic jets; aeroacoustics; twin square jets; turbulence tripping
- Teknisk mekanik
- Engineering Mechanics
- Aerospace Engineering
- Flyg- och rymdteknik
Publikations- och innehållstyp
- ref (ämneskategori)
- art (ämneskategori)
Hitta via bibliotek
Till lärosätets databas