Adapting a propeller noise model for aircraft at cruising altitudes
An existing propeller harmonic noise model is adapted to incorporate the effects of a stratified atmosphere so that predictions can be made of the ground-level noise for an aircraft flying at cruising altitudes. Specifically, the speed of sound and the atmospheric absorption are both made functions...
| Main Authors: | , , |
|---|---|
| Format: | Conference Paper |
| Published: |
2014
|
| Online Access: | http://hdl.handle.net/20.500.11937/52806 |
| _version_ | 1848759016006615040 |
|---|---|
| author | Blunt, D. Jones, Adrian Mewett, D. |
| author_facet | Blunt, D. Jones, Adrian Mewett, D. |
| author_sort | Blunt, D. |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | An existing propeller harmonic noise model is adapted to incorporate the effects of a stratified atmosphere so that predictions can be made of the ground-level noise for an aircraft flying at cruising altitudes. Specifically, the speed of sound and the atmospheric absorption are both made functions of altitude. The effects of refraction and ground reflection are examined, but deemed small enough to exclude from the initial model adaptation. The adapted model is applied to long-range acoustic data for a turboprop aircraft at three different cruising altitudes. The results show that a relatively good fit can be found between the model and the experimental data at the Doppler-shifted blade passing frequency within a range of source radiation angles from 30° to 110° with respect to the aircraft's direction of travel. The results also highlight the influence of molecular oxygen on the atmospheric absorption of the propeller harmonics. Recommendations are made for further improvements to the model. |
| first_indexed | 2025-11-14T09:53:10Z |
| format | Conference Paper |
| id | curtin-20.500.11937-52806 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T09:53:10Z |
| publishDate | 2014 |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-528062017-04-28T13:59:57Z Adapting a propeller noise model for aircraft at cruising altitudes Blunt, D. Jones, Adrian Mewett, D. An existing propeller harmonic noise model is adapted to incorporate the effects of a stratified atmosphere so that predictions can be made of the ground-level noise for an aircraft flying at cruising altitudes. Specifically, the speed of sound and the atmospheric absorption are both made functions of altitude. The effects of refraction and ground reflection are examined, but deemed small enough to exclude from the initial model adaptation. The adapted model is applied to long-range acoustic data for a turboprop aircraft at three different cruising altitudes. The results show that a relatively good fit can be found between the model and the experimental data at the Doppler-shifted blade passing frequency within a range of source radiation angles from 30° to 110° with respect to the aircraft's direction of travel. The results also highlight the influence of molecular oxygen on the atmospheric absorption of the propeller harmonics. Recommendations are made for further improvements to the model. 2014 Conference Paper http://hdl.handle.net/20.500.11937/52806 restricted |
| spellingShingle | Blunt, D. Jones, Adrian Mewett, D. Adapting a propeller noise model for aircraft at cruising altitudes |
| title | Adapting a propeller noise model for aircraft at cruising altitudes |
| title_full | Adapting a propeller noise model for aircraft at cruising altitudes |
| title_fullStr | Adapting a propeller noise model for aircraft at cruising altitudes |
| title_full_unstemmed | Adapting a propeller noise model for aircraft at cruising altitudes |
| title_short | Adapting a propeller noise model for aircraft at cruising altitudes |
| title_sort | adapting a propeller noise model for aircraft at cruising altitudes |
| url | http://hdl.handle.net/20.500.11937/52806 |