Record Details
Sediment transport beneath an undular hydraulic jump
ScholarsArchive at Oregon State University
| Field | Value |
|---|---|
| Title | Sediment transport beneath an undular hydraulic jump |
| Names |
Broome, Robert
(creator) Komar, Paul D. (advisor) |
| Date Issued | 1978-05-30 (iso8601) |
| Note | Graduation date: 1979 |
| Abstract | Field observations are made of the formation of backwash ripples on the beachface, formed by undular hydraulic jumps generated by backwash down the beach face colliding with wave bores. Measured ripple wavelengths range from set averages of 48 to 70 cm. Within a particular set of ripples there is a tendency for the spacing to decrease in the offshore direction. These field observations are compared with laboratory experiments where undular jumps are generated in a flume, and with a computer simulation model which models both the flow within an undular hydraulic jump and the resulting sediment transport which gives rise to the backwash ripples. The computer model involves a numerical solution of the Boussinesq equations which govern the fluid flow, and sediment transport equations which relate the sand transport rate to the local mean flow velocity. The computer model permits a study of the detailed time-history of the undular jump development and the formation of the backwash ripples. This model shows good agreement with the field observations of backwash ripples, predicting an offshore decrease in their spacing as observed. The laboratory experiments showed a similar result so long as the Froude number of the supercritical flow before the jump occurs is small, on the order of 1.4. Differences between the computer model and experiments were small and arose principally from the neglect of internal friction and surface tension in the model. The study demonstrates the usefulness of the simultaneous application of computer simulation models and laboratory experiments to understand complex flow and sediment transport conditions such as occur on beaches. |
| Genre | Thesis/Dissertation |
| Topic | Sediment transport |
| Identifier | http://hdl.handle.net/1957/28157 |
