Ultra Low Frequency Wave Produced by Underwater Oscillating Sphere and Its Measurement
When an underwater target moves in viscous fluid, it may cause the periodic movement of the surrounding fluid and generate ultra-low-frequency (ULF) gravity waves. The initial domain of the gravitational surface wave propagating above the moving target is named circular wave. This article studies th...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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MDPI AG
2021-11-01
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| Series: | Journal of Marine Science and Engineering |
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| Online Access: | https://www.mdpi.com/2077-1312/9/12/1317 |
| _version_ | 1797503347869089792 |
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| author | Huan Wang Erzheng Fang Mingze Wu Lianjin Hong Zongru Li |
| author_facet | Huan Wang Erzheng Fang Mingze Wu Lianjin Hong Zongru Li |
| author_sort | Huan Wang |
| collection | DOAJ |
| description | When an underwater target moves in viscous fluid, it may cause the periodic movement of the surrounding fluid and generate ultra-low-frequency (ULF) gravity waves. The initial domain of the gravitational surface wave propagating above the moving target is named circular wave. This article studies the ULF circular wave generated by underwater oscillating sphere, which will provide basis for underwater long-range target detection. Firstly, the circular wave caused by the sphere oscillation in a finite deep fluid is studied based on the theory of linear potential flow. Meanwhile, the multipole expansion theory is established to solve the circular wave field. Secondly, the interface wave generated by the target oscillation in a two-layer fluid are numerically analyzed by comparison with the free surface fluctuation of a single-layer fluid. The results show that the amplitude of the internal interface displacement (AIID) is smaller than that of the free surface (AFSD). When the sphere is in the lower layer, the layering effect of the fluid has significant influences on the AFSD. Finally, the results of the pool experiment verified that the wave generated by the oscillating sphere is the surface gravity wave. Furthermore, the change trend of the test result is consistent with the simulation result. |
| first_indexed | 2024-03-10T03:49:19Z |
| format | Article |
| id | doaj.art-f3b54a9486f24355b9b76d7549577cb1 |
| institution | Directory Open Access Journal |
| issn | 2077-1312 |
| language | English |
| last_indexed | 2024-03-10T03:49:19Z |
| publishDate | 2021-11-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Journal of Marine Science and Engineering |
| spelling | doaj.art-f3b54a9486f24355b9b76d7549577cb12023-11-23T09:01:59ZengMDPI AGJournal of Marine Science and Engineering2077-13122021-11-01912131710.3390/jmse9121317Ultra Low Frequency Wave Produced by Underwater Oscillating Sphere and Its MeasurementHuan Wang0Erzheng Fang1Mingze Wu2Lianjin Hong3Zongru Li4College of Underwater Acoustic Engineering, Harbin Engineering University, Harbin 150001, ChinaCollege of Underwater Acoustic Engineering, Harbin Engineering University, Harbin 150001, ChinaCollege of Underwater Acoustic Engineering, Harbin Engineering University, Harbin 150001, ChinaCollege of Underwater Acoustic Engineering, Harbin Engineering University, Harbin 150001, ChinaCollege of Underwater Acoustic Engineering, Harbin Engineering University, Harbin 150001, ChinaWhen an underwater target moves in viscous fluid, it may cause the periodic movement of the surrounding fluid and generate ultra-low-frequency (ULF) gravity waves. The initial domain of the gravitational surface wave propagating above the moving target is named circular wave. This article studies the ULF circular wave generated by underwater oscillating sphere, which will provide basis for underwater long-range target detection. Firstly, the circular wave caused by the sphere oscillation in a finite deep fluid is studied based on the theory of linear potential flow. Meanwhile, the multipole expansion theory is established to solve the circular wave field. Secondly, the interface wave generated by the target oscillation in a two-layer fluid are numerically analyzed by comparison with the free surface fluctuation of a single-layer fluid. The results show that the amplitude of the internal interface displacement (AIID) is smaller than that of the free surface (AFSD). When the sphere is in the lower layer, the layering effect of the fluid has significant influences on the AFSD. Finally, the results of the pool experiment verified that the wave generated by the oscillating sphere is the surface gravity wave. Furthermore, the change trend of the test result is consistent with the simulation result.https://www.mdpi.com/2077-1312/9/12/1317ultra low frequencysphere oscillationcircular wavetwo-layer fluid |
| spellingShingle | Huan Wang Erzheng Fang Mingze Wu Lianjin Hong Zongru Li Ultra Low Frequency Wave Produced by Underwater Oscillating Sphere and Its Measurement Journal of Marine Science and Engineering ultra low frequency sphere oscillation circular wave two-layer fluid |
| title | Ultra Low Frequency Wave Produced by Underwater Oscillating Sphere and Its Measurement |
| title_full | Ultra Low Frequency Wave Produced by Underwater Oscillating Sphere and Its Measurement |
| title_fullStr | Ultra Low Frequency Wave Produced by Underwater Oscillating Sphere and Its Measurement |
| title_full_unstemmed | Ultra Low Frequency Wave Produced by Underwater Oscillating Sphere and Its Measurement |
| title_short | Ultra Low Frequency Wave Produced by Underwater Oscillating Sphere and Its Measurement |
| title_sort | ultra low frequency wave produced by underwater oscillating sphere and its measurement |
| topic | ultra low frequency sphere oscillation circular wave two-layer fluid |
| url | https://www.mdpi.com/2077-1312/9/12/1317 |
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