Longshore sediment transport rate calculated incorporating wave orbital velocity fluctuations
Laboratory experiments were performed to study and improve longshore sediment transport rate predictions. Measured total longshore transport in the laboratory was approximately three times greater for plunging breakers than spilling breakers. Three distinct zones of longshore transport were observed...
Lưu vào:
| Tác giả chính: | |
|---|---|
| Định dạng: | Luận án |
| Ngôn ngữ: | en_US |
| Thông tin xuất bản: |
Texas A&M University
2007
|
| Chủ đề: | |
| Truy cập trực tuyến: | http://ir.vnulib.edu.vn/handle/123456789/1536 |
| Từ khóa: |
Thêm từ khóa bạn đọc
Không có từ khóa, Hãy là người đầu tiên gắn từ khóa cho biểu ghi này!
|
| id |
oai:192.168.1.90:123456789-1536 |
|---|---|
| record_format |
dspace |
| spelling |
oai:192.168.1.90:123456789-15362022-03-28T10:19:20Z Longshore sediment transport rate calculated incorporating wave orbital velocity fluctuations Smith, Ernest Ray Địa chất Longshore sediment Laboratory experiments were performed to study and improve longshore sediment transport rate predictions. Measured total longshore transport in the laboratory was approximately three times greater for plunging breakers than spilling breakers. Three distinct zones of longshore transport were observed across the surf zone: the incipient breaker zone, inner surf zone, and swash zone. Transport at incipient breaking was influenced by breaker type; inner surf zone transport was dominated by wave height, independent of wave period; and swash zone transport was dependent on wave period. Selected predictive formulas to compute total load and distributed load transport were compared to laboratory and field data. Equations by Kamphuis (1991) and Madsen et al. (2003) gave consistent total sediment transport estimates for both laboratory and field data. Additionally, the CERC formula predicted measurements well if calibrated and applied to similar breaker types. Each of the distributed load models had shortcomings. The energetics model of Bodge and Dean (1987) was sensitive to fluctuations in energy dissipation and often predicted transport peaks that were not present in the data. The Watanabe (1992) equation, based on time-averaged bottom stress, predicted no transport at most laboratory locations. The Van Rijn (1993) model was comprehensive and required hydrodynamic, bedform, and sediment data. The model estimated the laboratory cross-shore distribution well, but greatly overestimated field transport. Seven models were developed in this study based on the principle that transported sediment is mobilized by the total shear stress acting on the bottom and transported by the current at that location. Shear stress, including the turbulent component, was calculated from the wave orbital velocity. Models 1 through 3 gave good estimates of the transport distribution, but underpredicted the transport peak near the plunging wave breakpoint. A suspension term was included in Models 4 through 7, which improved estimates near breaking for plunging breakers. Models 4, 5 and 7 also compared well to the field measurements. It was concluded that breaker type is an important variable in determining the amount of transport that occurs at a location. Lastly, inclusion of the turbulent component of the orbital velocity is vital in predictive sediment transport equations. 2007-12-26T07:11:07Z 2007-12-26T07:11:07Z 2006 Thesis http://ir.vnulib.edu.vn/handle/123456789/1536 en_US Doctor of Philosophy application/pdf Texas A&M University |
| institution |
Đại học Quốc Gia Hồ Chí Minh |
| collection |
DSpace |
| language |
en_US |
| topic |
Địa chất Longshore sediment |
| spellingShingle |
Địa chất Longshore sediment Smith, Ernest Ray Longshore sediment transport rate calculated incorporating wave orbital velocity fluctuations |
| description |
Laboratory experiments were performed to study and improve longshore sediment transport rate predictions. Measured total longshore transport in the laboratory was approximately three times greater for plunging breakers than spilling breakers. Three distinct zones of longshore transport were observed across the surf zone: the incipient breaker zone, inner surf zone, and swash zone. Transport at incipient breaking was influenced by breaker type; inner surf zone transport was dominated by wave height, independent of wave period; and swash zone transport was dependent on wave period.
Selected predictive formulas to compute total load and distributed load transport were compared to laboratory and field data. Equations by Kamphuis (1991) and Madsen et al. (2003) gave consistent total sediment transport estimates for both laboratory and field data. Additionally, the CERC formula predicted measurements well if calibrated and applied to similar breaker types. Each of the distributed load models had shortcomings. The energetics model of Bodge and Dean (1987) was sensitive to fluctuations in energy dissipation and often predicted transport peaks that were not present in the data. The Watanabe (1992) equation, based on time-averaged bottom
stress, predicted no transport at most laboratory locations. The Van Rijn (1993) model was comprehensive and required hydrodynamic, bedform, and sediment data. The model estimated the laboratory cross-shore distribution well, but greatly overestimated field transport.
Seven models were developed in this study based on the principle that transported sediment is mobilized by the total shear stress acting on the bottom and transported by the current at that location. Shear stress, including the turbulent component, was calculated from the wave orbital velocity. Models 1 through 3 gave good estimates of the transport distribution, but underpredicted the transport peak near the plunging wave breakpoint. A suspension term was included in Models 4 through 7, which improved estimates near breaking for plunging breakers. Models 4, 5 and 7 also compared well to the field measurements.
It was concluded that breaker type is an important variable in determining the amount of transport that occurs at a location. Lastly, inclusion of the turbulent component of the orbital velocity is vital in predictive sediment transport equations. |
| format |
Thesis |
| author |
Smith, Ernest Ray |
| author_facet |
Smith, Ernest Ray |
| author_sort |
Smith, Ernest Ray |
| title |
Longshore sediment transport rate calculated incorporating wave orbital velocity fluctuations |
| title_short |
Longshore sediment transport rate calculated incorporating wave orbital velocity fluctuations |
| title_full |
Longshore sediment transport rate calculated incorporating wave orbital velocity fluctuations |
| title_fullStr |
Longshore sediment transport rate calculated incorporating wave orbital velocity fluctuations |
| title_full_unstemmed |
Longshore sediment transport rate calculated incorporating wave orbital velocity fluctuations |
| title_sort |
longshore sediment transport rate calculated incorporating wave orbital velocity fluctuations |
| publisher |
Texas A&M University |
| publishDate |
2007 |
| url |
http://ir.vnulib.edu.vn/handle/123456789/1536 |
| work_keys_str_mv |
AT smithernestray longshoresedimenttransportratecalculatedincorporatingwaveorbitalvelocityfluctuations |
| _version_ |
1749008378847297536 |