| Author | Dang Van To. |
| Call Number | AIT Thesis no. WA-93-5 |
| Subject(s) | Sediment transport.
|
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science. |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. WA-93-5 |
| Abstract | While the sediment movement under waves or steady current was investigated, very little attention has been paid to the initial motion under combination of waves and current. In this study, the previous work at first of Madsen and Grant (1976) in which they used the friction factor of Jonsson (1966) under oscillatory flows are re-analyzed by the recent explicit friction coefficient proposed by Thu (1992). General motion, critical water depth under waves and the initial motion of wave-current combination then are investigated. It is found that the criterion curve for initial motion and general motion could be obtained analytically by regression. Both of present results under waves alone and wave-current combination are slightly shifted downward. Critical water depth diagram is proposed on the basis of those from Horikawa and Watanabe (1967). Secondly, the results of experimental data are analyzed by the diagram spanning all flow regimes proposed by Thu (1992). It points out that most of them are felt in the transitional region. Finally, modification of reduction coefficient based on the study of Tanaka & Shuto (1984) is derived for the geometry of sand ripples generated by waves and current by using laboratory data collected from various recent researchers. The calculated ripple length is improved considerably by using just obtained reduction coefficient, which includes the effect of grain sizes. The explicit friction coefficient used to evaluate the bottom shear stress and ripple steepness confirms the validity of previous empirical curves proposed by Tanaka and Shuto (1984). |
| Year | 1993 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. WA-93-5 |
| Type | Thesis |
| School | School of Engineering and Technology (SET) |
| Department | Department of Civil and Infrastucture Engineering (DCIE) |
| Academic Program/FoS | Water Resources Research Engineering (WA) |
| Chairperson(s) | Tanaka, Hitosbi. |
| Examination Committee(s) | Supbat Vongvisessomjai;Tawatcbai Tingsanchali;Sutat Weesakul |
| Scholarship Donor(s) | Government of New Zealand. |
| Degree | Thesis (M.Sc.) - Asian Institute of Technology, 1993 |