Frey, Christian und Geihe, Benedict und Junge, Laura (2022) Analyzing unsteady turbomachinery flow simulations with mixing entropy. In: Proceedings of the 16th International Symposium on Unsteady Aerodynamics Aeroacoustics & Aeroelasticity of Turbomachines ISUAAAT16. 16th International Symposium on Unsteady Aerodynamics Aeroacoustics & Aeroelasticity of Turbomachines ISUAAAT16, 2022-09-19 - 2022-09-23, Toledo, Spain.
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Kurzfassung
The prediction of unsteady aerodynamic loads is a central problem during the design of turbomachinery. Over the last 20 years, harmonic balance methods have been shown to be highly efficient for this task. A CPU-cost optimal setup of a harmonic balance simulation, however, requires the knowledge about relevant harmonics. In the case of a single blade row with a periodic disturbance this question amounts to the classical problem of harmonic convergence, a problem which is solely due to the nonlinearity of the unsteady flow physics. In contrast, for multi-stage configurations, the choice of harmonics is further complicated by the fact that the interactions of disturbances with blade rows may give rise to a vast spectrum of harmonics that possibly have important modal content, e.g. Tyler-Sofrin modes. The aim of this paper is to show that the mixing entropy attributed to circumferential modes of a given harmonic can serve as a disturbance metric on the basis of which a criterion could be derived whether a certain harmonic should be included or not. The idea is based on the observation that the entropy due to the temporal and circumferential mixing of the flow at a blade row interface may be decomposed, up to third-order terms, into independent contributions from different frequencies and mode orders. For a given harmonic balance (and steady) flow result, the mixing entropy attributed to modes which are simply mixed out, rather than resolved in the neighbouring row, is shown to be a natural indicator of a potential inaccuracy. We present important features of the mixing entropy for unsteady disturbances, in particular a close relationship to sound power for acoustic modes. The problem of mode selection in a 1.5-stage compressor configuration serves as a practical example to illustrate our findings.
elib-URL des Eintrags: | https://elib.dlr.de/192130/ | ||||||||||||||||
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Dokumentart: | Konferenzbeitrag (Vortrag) | ||||||||||||||||
Titel: | Analyzing unsteady turbomachinery flow simulations with mixing entropy | ||||||||||||||||
Autoren: |
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Datum: | 2022 | ||||||||||||||||
Erschienen in: | Proceedings of the 16th International Symposium on Unsteady Aerodynamics Aeroacoustics & Aeroelasticity of Turbomachines ISUAAAT16 | ||||||||||||||||
Referierte Publikation: | Ja | ||||||||||||||||
Open Access: | Ja | ||||||||||||||||
Gold Open Access: | Nein | ||||||||||||||||
In SCOPUS: | Nein | ||||||||||||||||
In ISI Web of Science: | Nein | ||||||||||||||||
Status: | akzeptierter Beitrag | ||||||||||||||||
Stichwörter: | Computational fluid dynamics (CFD), mixing entropy, harmonic balance, turbomachinery | ||||||||||||||||
Veranstaltungstitel: | 16th International Symposium on Unsteady Aerodynamics Aeroacoustics & Aeroelasticity of Turbomachines ISUAAAT16 | ||||||||||||||||
Veranstaltungsort: | Toledo, Spain | ||||||||||||||||
Veranstaltungsart: | internationale Konferenz | ||||||||||||||||
Veranstaltungsbeginn: | 19 September 2022 | ||||||||||||||||
Veranstaltungsende: | 23 September 2022 | ||||||||||||||||
HGF - Forschungsbereich: | Luftfahrt, Raumfahrt und Verkehr | ||||||||||||||||
HGF - Programm: | Luftfahrt | ||||||||||||||||
HGF - Programmthema: | Umweltschonender Antrieb | ||||||||||||||||
DLR - Schwerpunkt: | Luftfahrt | ||||||||||||||||
DLR - Forschungsgebiet: | L CP - Umweltschonender Antrieb | ||||||||||||||||
DLR - Teilgebiet (Projekt, Vorhaben): | L - Virtuelles Triebwerk | ||||||||||||||||
Standort: | Köln-Porz | ||||||||||||||||
Institute & Einrichtungen: | Institut für Antriebstechnik > Numerische Methoden | ||||||||||||||||
Hinterlegt von: | Frey, Christian | ||||||||||||||||
Hinterlegt am: | 12 Dez 2022 09:40 | ||||||||||||||||
Letzte Änderung: | 24 Apr 2024 20:53 |
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