Non-Hydrostatic Numerical Model of Bragg Resonance on Periodically Submerged Breakwater
The Bragg resonance (BR) of a reflection coefficient resulting from the propagation of monochronic waves over periodically submerged breakwater was studied using the non-hydrostatic numerical model SWASH (Simulating WAves till SHore). Bragg resonance occurs when the incident wavelength is approximat...
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-03-01
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| Series: | Journal of Marine Science and Engineering |
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| Online Access: | https://www.mdpi.com/2077-1312/11/3/650 |
| _version_ | 1827749262978449408 |
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| author | Tolulope Emmanuel Oginni Xizeng Zhao |
| author_facet | Tolulope Emmanuel Oginni Xizeng Zhao |
| author_sort | Tolulope Emmanuel Oginni |
| collection | DOAJ |
| description | The Bragg resonance (BR) of a reflection coefficient resulting from the propagation of monochronic waves over periodically submerged breakwater was studied using the non-hydrostatic numerical model SWASH (Simulating WAves till SHore). Bragg resonance occurs when the incident wavelength is approximately twice the structural length of a periodic structural breakwater according to Bragg’s law and conditions. This study aimed to investigate the dynamics of Bragg resonance at water depths of 0.2, 0.3, and 0.4 m as the number of periodically submerged breakwater and their wavelengths changed. Specifically, this study focused on the Bragg resonance point of occurrence at a ratio of two structural wavelengths to the incoming wavelengths (2<i>S/L</i>). Regular waves were propagated over two periodically submerged breakwaters, with increasing structural wavelengths from 1 to 2 m at 0.2 m intervals. The results showed that Bragg resonances rapidly increase in value as the water depth decreases, but do not shift in their point of occurrence as the number of periodically submerged breakwaters increases. However, the Bragg resonance shifts leftward in <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>2</mn><mi>S</mi><mo>/</mo><mi>L</mi></mrow></semantics></math></inline-formula> as the structural wavelength increases, with a slight increase in value at shallower water depths. More incident wave energy is reflected when the number of periodically submerged breakwater increases compared with when the structural wavelength of the periodically submerged breakwater increases. The differences in the Bragg resonance values are associated with the changes in the number of periodically submerged breakwater. Additionally, the shift in the point of occurrence was influenced by both water depth and structural length. This causes the Resulted Bragg resonance to deviate from the Expected Bragg resonance, which could be the reason why Bragg resonance does not mainly occur at <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>2</mn><mi>S</mi><mo>/</mo><mi>L</mi><mo>=</mo><mn>1</mn></mrow></semantics></math></inline-formula>, as stated by Bragg’s law. |
| first_indexed | 2024-03-11T06:20:21Z |
| format | Article |
| id | doaj.art-9ce629c44be84f79ad711d4c6f6ac560 |
| institution | Directory Open Access Journal |
| issn | 2077-1312 |
| language | English |
| last_indexed | 2024-03-11T06:20:21Z |
| publishDate | 2023-03-01 |
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| series | Journal of Marine Science and Engineering |
| spelling | doaj.art-9ce629c44be84f79ad711d4c6f6ac5602023-11-17T11:58:33ZengMDPI AGJournal of Marine Science and Engineering2077-13122023-03-0111365010.3390/jmse11030650Non-Hydrostatic Numerical Model of Bragg Resonance on Periodically Submerged BreakwaterTolulope Emmanuel Oginni0Xizeng Zhao1Ocean College, Zhejiang University, Zhoushan 316021, ChinaOcean College, Zhejiang University, Zhoushan 316021, ChinaThe Bragg resonance (BR) of a reflection coefficient resulting from the propagation of monochronic waves over periodically submerged breakwater was studied using the non-hydrostatic numerical model SWASH (Simulating WAves till SHore). Bragg resonance occurs when the incident wavelength is approximately twice the structural length of a periodic structural breakwater according to Bragg’s law and conditions. This study aimed to investigate the dynamics of Bragg resonance at water depths of 0.2, 0.3, and 0.4 m as the number of periodically submerged breakwater and their wavelengths changed. Specifically, this study focused on the Bragg resonance point of occurrence at a ratio of two structural wavelengths to the incoming wavelengths (2<i>S/L</i>). Regular waves were propagated over two periodically submerged breakwaters, with increasing structural wavelengths from 1 to 2 m at 0.2 m intervals. The results showed that Bragg resonances rapidly increase in value as the water depth decreases, but do not shift in their point of occurrence as the number of periodically submerged breakwaters increases. However, the Bragg resonance shifts leftward in <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>2</mn><mi>S</mi><mo>/</mo><mi>L</mi></mrow></semantics></math></inline-formula> as the structural wavelength increases, with a slight increase in value at shallower water depths. More incident wave energy is reflected when the number of periodically submerged breakwater increases compared with when the structural wavelength of the periodically submerged breakwater increases. The differences in the Bragg resonance values are associated with the changes in the number of periodically submerged breakwater. Additionally, the shift in the point of occurrence was influenced by both water depth and structural length. This causes the Resulted Bragg resonance to deviate from the Expected Bragg resonance, which could be the reason why Bragg resonance does not mainly occur at <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>2</mn><mi>S</mi><mo>/</mo><mi>L</mi><mo>=</mo><mn>1</mn></mrow></semantics></math></inline-formula>, as stated by Bragg’s law.https://www.mdpi.com/2077-1312/11/3/650Bragg resonancereflection coefficientmonochronic wavesperiodically submerged breakwaterBragg’s lawnon-hydrostatic |
| spellingShingle | Tolulope Emmanuel Oginni Xizeng Zhao Non-Hydrostatic Numerical Model of Bragg Resonance on Periodically Submerged Breakwater Journal of Marine Science and Engineering Bragg resonance reflection coefficient monochronic waves periodically submerged breakwater Bragg’s law non-hydrostatic |
| title | Non-Hydrostatic Numerical Model of Bragg Resonance on Periodically Submerged Breakwater |
| title_full | Non-Hydrostatic Numerical Model of Bragg Resonance on Periodically Submerged Breakwater |
| title_fullStr | Non-Hydrostatic Numerical Model of Bragg Resonance on Periodically Submerged Breakwater |
| title_full_unstemmed | Non-Hydrostatic Numerical Model of Bragg Resonance on Periodically Submerged Breakwater |
| title_short | Non-Hydrostatic Numerical Model of Bragg Resonance on Periodically Submerged Breakwater |
| title_sort | non hydrostatic numerical model of bragg resonance on periodically submerged breakwater |
| topic | Bragg resonance reflection coefficient monochronic waves periodically submerged breakwater Bragg’s law non-hydrostatic |
| url | https://www.mdpi.com/2077-1312/11/3/650 |
| work_keys_str_mv | AT tolulopeemmanueloginni nonhydrostaticnumericalmodelofbraggresonanceonperiodicallysubmergedbreakwater AT xizengzhao nonhydrostaticnumericalmodelofbraggresonanceonperiodicallysubmergedbreakwater |