Underwater Sound Characteristics of a Ship with Controllable Pitch Propeller
The time-dependent spectral characteristics of underwater sound radiated by an ocean vessel has complex dependencies on ship machinery, propeller dynamics, hydrodynamics of ship exhaust and motion, as well as ship board activities. Here the underwater sound radiated by a ship equipped with a control...
| Main Authors: | , , , |
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| Format: | Article |
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Multidisciplinary Digital Publishing Institute
2022
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| Online Access: | https://hdl.handle.net/1721.1/141117 |
| _version_ | 1811071149902135296 |
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| author | Zhu, Chenyang Gaggero, Tomaso Makris, Nicholas C. Ratilal, Purnima |
| author2 | Massachusetts Institute of Technology. Department of Mechanical Engineering |
| author_facet | Massachusetts Institute of Technology. Department of Mechanical Engineering Zhu, Chenyang Gaggero, Tomaso Makris, Nicholas C. Ratilal, Purnima |
| author_sort | Zhu, Chenyang |
| collection | MIT |
| description | The time-dependent spectral characteristics of underwater sound radiated by an ocean vessel has complex dependencies on ship machinery, propeller dynamics, hydrodynamics of ship exhaust and motion, as well as ship board activities. Here the underwater sound radiated by a ship equipped with a controllable pitch propeller (CPP) is analyzed and quantified via its (i) power spectral density for signal energetics, (ii) temporal coherence for machinery tonal sound, and (iii) spectral coherence for propeller amplitude-modulated cavitation noise. Frequency-modulated (FM) tonal signals are also characterized in terms of their frequency variations. These characteristics are compared for different propeller pitch ratios ranging from 20% to 82% at fixed propeller revolutions per minute (RPM). The efficacy and robustness of ship parameter estimation at different pitches are discussed. Finally, analysis of one special measurement is provided, when ship changes speed, propeller pitch and RPM over the duration of the measurement. The 50% pitch is found to be a crucial point for this ship about which tonal characteristics of its underwater radiated sound attain their peak values, while broadband sound and associated spectral coherences are at a minimum. The findings here elucidate the effects of pitch variation on underwater sound radiated by ships with controllable pitch propellers and has applications in ship design and underwater noise mitigation. |
| first_indexed | 2024-09-23T08:46:48Z |
| format | Article |
| id | mit-1721.1/141117 |
| institution | Massachusetts Institute of Technology |
| last_indexed | 2024-09-23T08:46:48Z |
| publishDate | 2022 |
| publisher | Multidisciplinary Digital Publishing Institute |
| record_format | dspace |
| spelling | mit-1721.1/1411172023-03-28T19:49:39Z Underwater Sound Characteristics of a Ship with Controllable Pitch Propeller Zhu, Chenyang Gaggero, Tomaso Makris, Nicholas C. Ratilal, Purnima Massachusetts Institute of Technology. Department of Mechanical Engineering The time-dependent spectral characteristics of underwater sound radiated by an ocean vessel has complex dependencies on ship machinery, propeller dynamics, hydrodynamics of ship exhaust and motion, as well as ship board activities. Here the underwater sound radiated by a ship equipped with a controllable pitch propeller (CPP) is analyzed and quantified via its (i) power spectral density for signal energetics, (ii) temporal coherence for machinery tonal sound, and (iii) spectral coherence for propeller amplitude-modulated cavitation noise. Frequency-modulated (FM) tonal signals are also characterized in terms of their frequency variations. These characteristics are compared for different propeller pitch ratios ranging from 20% to 82% at fixed propeller revolutions per minute (RPM). The efficacy and robustness of ship parameter estimation at different pitches are discussed. Finally, analysis of one special measurement is provided, when ship changes speed, propeller pitch and RPM over the duration of the measurement. The 50% pitch is found to be a crucial point for this ship about which tonal characteristics of its underwater radiated sound attain their peak values, while broadband sound and associated spectral coherences are at a minimum. The findings here elucidate the effects of pitch variation on underwater sound radiated by ships with controllable pitch propellers and has applications in ship design and underwater noise mitigation. 2022-03-10T16:28:39Z 2022-03-10T16:28:39Z 2022-02-25 2022-03-10T14:18:34Z Article http://purl.org/eprint/type/JournalArticle https://hdl.handle.net/1721.1/141117 Journal of Marine Science and Engineering 10 (3): 328 (2022) PUBLISHER_CC http://dx.doi.org/10.3390/jmse10030328 Creative Commons Attribution https://creativecommons.org/licenses/by/4.0/ application/pdf Multidisciplinary Digital Publishing Institute Multidisciplinary Digital Publishing Institute |
| spellingShingle | Zhu, Chenyang Gaggero, Tomaso Makris, Nicholas C. Ratilal, Purnima Underwater Sound Characteristics of a Ship with Controllable Pitch Propeller |
| title | Underwater Sound Characteristics of a Ship with Controllable Pitch Propeller |
| title_full | Underwater Sound Characteristics of a Ship with Controllable Pitch Propeller |
| title_fullStr | Underwater Sound Characteristics of a Ship with Controllable Pitch Propeller |
| title_full_unstemmed | Underwater Sound Characteristics of a Ship with Controllable Pitch Propeller |
| title_short | Underwater Sound Characteristics of a Ship with Controllable Pitch Propeller |
| title_sort | underwater sound characteristics of a ship with controllable pitch propeller |
| url | https://hdl.handle.net/1721.1/141117 |
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