A laboratory study on the sandy ripples' processes and effects on the wave field due to the water wave action
碩士 === 淡江大學 === 水資源及環境工程學系 === 86 === In the aspect of engineering application,the existence of the ripples will affect the on-offshore sediment transporting direction . The ripples may also be one of the major factors of which may affect t...
| Main Authors: | , |
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| Other Authors: | |
| Format: | Others |
| Language: | zh-TW |
| Published: |
1998
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| Online Access: | http://ndltd.ncl.edu.tw/handle/22869789889034458620 |
| Summary: | 碩士 === 淡江大學 === 水資源及環境工程學系 === 86 === In the aspect of engineering application,the existence of the
ripples will affect the on-offshore sediment transporting
direction . The ripples may also be one of the major factors of
which may affect the quality of sediment transportation.In this
study, the flow visualization technique is utilized to obtain an
elementary knowledge about the transient processes until mature
sandy ripples being formed.The mature wavelength and wave height
of ripples are ripples being formed. The mature wavelength and
waveheight of ripples are also made by using a/D50 and
Shields parameter φ. The experimental relationships between
the ripple geometry and hydraulic parameters were derived. The
effects due to the existence of the ripples on the changes of
wave heights are also studied in order to estimate the related
friction factor . In which functional relationships between
the ripple geometry and hydraulic parameters were derived as
fw=1.5468(η^2/a*λ)^0.64 . The results of moving bed
experiments are smallthan the former results of fixed
artificial rippled shear plate . The form roughness can be
calculated from Swart's formula (1976) , and Ks is about 0.9~2.7
η. The experimental results reveal that the relation between
the equivalent form roughness Ks/ηand Shields parameter φ is
Ks/η=7.8φ^0.837 .
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