Near-bottom flow characteristics of currents at arbitrary angle to 2D ripples
Experimental results for near-bottom current velocity profiles for flows over artificial, definitely 2D ripples made of 1.5 cm high aluminum angle -profile spaced at 10 cm intervals are obtained for the following cases: (i)current alone perpendicular to ripples; (ii) current alone parallel to ripple...
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| Format: | Article |
| Language: | en_US |
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Coastal Engineering Research Council
2013
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| Online Access: | http://hdl.handle.net/1721.1/77986 https://orcid.org/0000-0002-6984-6499 |
| _version_ | 1826210148358553600 |
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| author | Madsen, Ole S. Negara, Arlendenovega Satria Lim, Kian Yew Cheong, Hin Fatt |
| author2 | Massachusetts Institute of Technology. Department of Civil and Environmental Engineering |
| author_facet | Massachusetts Institute of Technology. Department of Civil and Environmental Engineering Madsen, Ole S. Negara, Arlendenovega Satria Lim, Kian Yew Cheong, Hin Fatt |
| author_sort | Madsen, Ole S. |
| collection | MIT |
| description | Experimental results for near-bottom current velocity profiles for flows over artificial, definitely 2D ripples made of 1.5 cm high aluminum angle -profile spaced at 10 cm intervals are obtained for the following cases: (i)current alone perpendicular to ripples; (ii) current alone parallel to ripples; (iii) combined orthogonal wave-current flows for current parallel to ripples; and (iv) current alone at an angle of 30° to the ripple axis. The velocity profiles are analyzed by the log-profile method, and show the roughness experienced by the current to increase as the angle between ripple and current direction increases, i.e. demonstrating convincingly the reality of the concept of a direction-dependent roughness for flows over a 2D rippled bottom. Roughness experienced by the velocity component perpendicular to the ripples is, however, found to be independent of the direction of the mainstream flow relative to that of the ripples, and the different roughness experienced by the perpendicular and parallel velocity components gives rise to a turning of the current velocity vector to become increasingly aligned with the ripple crests as the bottom is approached from above. Implications of this feature, in terms of net sediment transport direction in combined wave-current flows in inner-shelf coastal waters, is discussed. |
| first_indexed | 2024-09-23T14:44:39Z |
| format | Article |
| id | mit-1721.1/77986 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T14:44:39Z |
| publishDate | 2013 |
| publisher | Coastal Engineering Research Council |
| record_format | dspace |
| spelling | mit-1721.1/779862022-10-01T22:13:01Z Near-bottom flow characteristics of currents at arbitrary angle to 2D ripples Madsen, Ole S. Negara, Arlendenovega Satria Lim, Kian Yew Cheong, Hin Fatt Massachusetts Institute of Technology. Department of Civil and Environmental Engineering Parsons Laboratory for Environmental Science and Engineering (Massachusetts Institute of Technology) Madsen, Ole S. Experimental results for near-bottom current velocity profiles for flows over artificial, definitely 2D ripples made of 1.5 cm high aluminum angle -profile spaced at 10 cm intervals are obtained for the following cases: (i)current alone perpendicular to ripples; (ii) current alone parallel to ripples; (iii) combined orthogonal wave-current flows for current parallel to ripples; and (iv) current alone at an angle of 30° to the ripple axis. The velocity profiles are analyzed by the log-profile method, and show the roughness experienced by the current to increase as the angle between ripple and current direction increases, i.e. demonstrating convincingly the reality of the concept of a direction-dependent roughness for flows over a 2D rippled bottom. Roughness experienced by the velocity component perpendicular to the ripples is, however, found to be independent of the direction of the mainstream flow relative to that of the ripples, and the different roughness experienced by the perpendicular and parallel velocity components gives rise to a turning of the current velocity vector to become increasingly aligned with the ripple crests as the bottom is approached from above. Implications of this feature, in terms of net sediment transport direction in combined wave-current flows in inner-shelf coastal waters, is discussed. Singapore–MIT Alliance for Research and Technology ((SMART) Center for Environmental Sensing and Modeling) Singapore. National Research Foundation 2013-03-22T18:06:33Z 2013-03-22T18:06:33Z 2010-07 Article http://purl.org/eprint/type/ConferencePaper 0893-8717 0161-3782 http://hdl.handle.net/1721.1/77986 Madsen, Ole Secher, Arlendenovega Satria Negara, Kian Yew Lim, and Hin Fatt Cheong. "Near-bottom flow characteristics of currents at arbitrary angle to 2D ripples." Proceedings of 32nd Conference on Coastal Engineering, July 1-7, 2010, Shanghai, China, 2010. https://orcid.org/0000-0002-6984-6499 en_US http://journals.tdl.org/icce/index.php/icce/article/view/1386/pdf_365 Proceedings of the 32nd International Conference on Coastal Engineering, ICCE 2010 Creative Commons Attribution-Noncommercial-Share Alike 3.0 http://creativecommons.org/licenses/by-nc-sa/3.0/ application/pdf Coastal Engineering Research Council MIT web domain |
| spellingShingle | Madsen, Ole S. Negara, Arlendenovega Satria Lim, Kian Yew Cheong, Hin Fatt Near-bottom flow characteristics of currents at arbitrary angle to 2D ripples |
| title | Near-bottom flow characteristics of currents at arbitrary angle to 2D ripples |
| title_full | Near-bottom flow characteristics of currents at arbitrary angle to 2D ripples |
| title_fullStr | Near-bottom flow characteristics of currents at arbitrary angle to 2D ripples |
| title_full_unstemmed | Near-bottom flow characteristics of currents at arbitrary angle to 2D ripples |
| title_short | Near-bottom flow characteristics of currents at arbitrary angle to 2D ripples |
| title_sort | near bottom flow characteristics of currents at arbitrary angle to 2d ripples |
| url | http://hdl.handle.net/1721.1/77986 https://orcid.org/0000-0002-6984-6499 |
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