| 1. |
- Bayram, Atilla, et al.
(författare)
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A new formula for the total longshore sediment transport rate
- 2007
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Ingår i: Coastal Engineering. - : Elsevier BV. - 0378-3839. ; 54:9, s. 700-710
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Tidskriftsartikel (refereegranskat)abstract
- A new predictive formula for the total longshore sediment transport (LST) rate was developed from principles of sediment transport physics assuming that breaking waves mobilize the sediment, which is subsequently moved by a mean current. Six high-quality data sets on hydrodynamics and sediment transport collected during both field and laboratory conditions were employed to evaluate the predictive capability of the new formula. The main parameter of the formula (a transport coefficient), which represents the efficiency of the waves in keeping sand grains in suspension, was expressed through a Dean number based on dimensional analysis. The new formula yields predictions that lie within a factor of 0.5 to 2 of the measured values for 62% of the data points, which is higher than other commonly employed formulas for the LST rate such as the CERC equation or the formulas developed by Inman-Bagnold and Kamphuis, respectively. The new formula is well suited for practical applications in coastal areas, as well as for numerical modeling of sediment transport and shoreline change in the nearshore. (c) 2007 Elsevier B.V. All rights reserved.
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| 2. |
- Camenen, Benoit, et al.
(författare)
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Equivalent roughness height for plane bed under oscillatory flow
- 2009
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Ingår i: Estuarine, Coastal and Shelf Science. - : Elsevier BV. - 1096-0015 .- 0272-7714. ; 81:3, s. 409-422
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Tidskriftsartikel (refereegranskat)abstract
- A new relationship between the roughness height and the main hydrodynamic and sediment parameters for plane beds under oscillatory conditions is presented. In order to derive such a relationship, a large data base encompassing plane-bed experiments was compiled from previous investigations and analyzed. Different methods to estimate the roughness height were investigated. Comparisons between the data and different existing predictive formulas for the bed roughness obtained from the literature were also performed. A relationship involving the grain size and Shields parameter only, which is commonly proposed, appeared to be insufficient to characterize the roughness. The roughness height was also found to be a function of the sediment density and the settling velocity. A critical Shields parameter was identified up to which the effective roughness ratio is proportional to the Shields parameter only. The new empirical equation developed in this study provides the highest predictive skill for all conditions investigated. (c) 2008 Elsevier Ltd. All rights reserved.
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| 3. |
- Camenen, Benoit, et al.
(författare)
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Equivalent roughness height for plane bed under steady flow
- 2006
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Ingår i: Journal of Hydraulic Engineering. - 1943-7900. ; 132:11, s. 1146-1158
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents a new relationship between the roughness height and the main hydrodynamic and sediment parameters for plane beds under steady current conditions. In order to derive such a formula, a large data base involving plane-bed experiments was compiled from previous investigations and analyzed. Comparisons between the data and different existing predictive formulas for the bed roughness obtained from the literature were also made. A relationship with the Shields parameter only, which is commonly proposed, appeared to be insufficient. The roughness was also found to be a function of a Froude number and a dimensionless settling velocity. A critical Shields parameter was identified up to which the equivalent roughness ratio is proportional to the Shields parameter. The new empirical equation that was developed yields the best results for all conditions investigated, and should improve the understanding of the total shear stress.
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| 4. |
- Larson, Magnus, et al.
(författare)
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An analytical model to predict dune and cliff notching due to wave impact
- 2010
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Ingår i: Proceedings of 32nd Conference on Coastal Engineering. - : Coastal Engineering Research Council. - 0161-3782. - 9781629931210 - 9780989661102
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Konferensbidrag (refereegranskat)abstract
- A model was developed to calculate the evolution of a notch in a dune or cliff due to wave impact. Analytical solutions were derived to the model for schematized conditions regarding forcing and dune/cliff properties. Comparisons were made with laboratory experiments where the time evolution of the notch was measured. Values of the transport coefficients in the analytical solutions were determined by least-square fitting the solutions to the laboratory data. Some of these coefficients could be related to the ratio between parameters describing the forcing and the dune/cliff strength. The evolution of the dune notch displayed a linear behavior at short times, whereas the cliff notch showed a more complex response for cases where a feedback between the notch and a beach formed seaward of the cliff occurred.
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