Full Text Available
Note: Clicking the button above will open the full text document at the original institutional repository in a new window.
Computational aeroacoustic modelling using hybrid RANS/LES methods with modified acoustic analogies
This study considers a numerical approach to identifying noise mechanisms in tandem cylinders to understand aircraft landing gear as a primary contributor to airframe noise during approach and landing. Fluctuations in the flow properties induced by turbulence are computed as well as the correspondin...
Saved in:
| Main Author: | |
|---|---|
| Other Authors: | |
| Format: | Thesis |
| Language: | English |
| Published: |
Department of Mathematics and Applied Mathematics
2017
|
| Subjects: | |
| Tags: |
No Tags, Be the first to tag this record!
|
| _version_ | 1867613310310940672 |
|---|---|
| access_status_str | Open Access |
| author | Nyandeni, Zamashobane |
| author2 | Chinyoka, Tirivanhu |
| author_browse | Chinyoka, Tirivanhu Nyandeni, Zamashobane |
| author_facet | Chinyoka, Tirivanhu Nyandeni, Zamashobane |
| author_sort | Nyandeni, Zamashobane |
| collection | Thesis |
| description | This study considers a numerical approach to identifying noise mechanisms in tandem cylinders to understand aircraft landing gear as a primary contributor to airframe noise during approach and landing. Fluctuations in the flow properties induced by turbulence are computed as well as the corresponding propagations. A hybrid IDDES turbulence model is employed, to compute the boundary layer and fluctuations in the flow properties. Larsson et al. modified Curle's analogy leading to the derivation of a version of Curle's analogy that makes use of strictly time derivatives which has been proven to be less sensitive to numerical errors. Brentner and Farassat derived a formulation of the Ffowcs-Williams and Hawkings analogy for a permeable surface enclosing the acoustic sources which accounts for the quadrupole acoustic sources in the flow without the costly calculation of a volume integral. This study will consider the impact of neglecting the volume sources through a comparison of the two modified versions of Curle's and FWH analogies with the results of other CFD practitioners as well as experimental data. |
| format | Thesis |
| id | oai:open.uct.ac.za:11427/25388 |
| institution | University of Cape Town (South Africa) |
| language | eng |
| last_indexed | 2026-06-10T12:34:06.076Z |
| license_str | Not specified — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UCTD — University of Cape Town Open Access Repository |
| publishDate | 2017 |
| publishDateRange | 2017 |
| publishDateSort | 2017 |
| publisher | Department of Mathematics and Applied Mathematics |
| publisherStr | Department of Mathematics and Applied Mathematics |
| record_format | dspace |
| source_str | UCTD — University of Cape Town Open Access Repository |
| spelling | oai:open.uct.ac.za:11427/25388 Computational aeroacoustic modelling using hybrid RANS/LES methods with modified acoustic analogies Nyandeni, Zamashobane Chinyoka, Tirivanhu Mathematics and Appplied Mathematics This study considers a numerical approach to identifying noise mechanisms in tandem cylinders to understand aircraft landing gear as a primary contributor to airframe noise during approach and landing. Fluctuations in the flow properties induced by turbulence are computed as well as the corresponding propagations. A hybrid IDDES turbulence model is employed, to compute the boundary layer and fluctuations in the flow properties. Larsson et al. modified Curle's analogy leading to the derivation of a version of Curle's analogy that makes use of strictly time derivatives which has been proven to be less sensitive to numerical errors. Brentner and Farassat derived a formulation of the Ffowcs-Williams and Hawkings analogy for a permeable surface enclosing the acoustic sources which accounts for the quadrupole acoustic sources in the flow without the costly calculation of a volume integral. This study will consider the impact of neglecting the volume sources through a comparison of the two modified versions of Curle's and FWH analogies with the results of other CFD practitioners as well as experimental data. 2017-09-26T14:50:08Z 2017-09-26T14:50:08Z 2017 Master Thesis Masters MSc http://hdl.handle.net/11427/25388 eng application/pdf Department of Mathematics and Applied Mathematics Faculty of Science University of Cape Town |
| spellingShingle | Mathematics and Appplied Mathematics Nyandeni, Zamashobane Computational aeroacoustic modelling using hybrid RANS/LES methods with modified acoustic analogies |
| thesis_degree_str | Master's |
| title | Computational aeroacoustic modelling using hybrid RANS/LES methods with modified acoustic analogies |
| title_full | Computational aeroacoustic modelling using hybrid RANS/LES methods with modified acoustic analogies |
| title_fullStr | Computational aeroacoustic modelling using hybrid RANS/LES methods with modified acoustic analogies |
| title_full_unstemmed | Computational aeroacoustic modelling using hybrid RANS/LES methods with modified acoustic analogies |
| title_short | Computational aeroacoustic modelling using hybrid RANS/LES methods with modified acoustic analogies |
| title_sort | computational aeroacoustic modelling using hybrid rans les methods with modified acoustic analogies |
| topic | Mathematics and Appplied Mathematics |
| url | http://hdl.handle.net/11427/25388 |
| work_keys_str_mv | AT nyandenizamashobane computationalaeroacousticmodellingusinghybridranslesmethodswithmodifiedacousticanalogies |