Effective roughness height in high-concentrated flows

Effective roughness height in high-concentrated flows

Fang, Jiayu (Hohai University)
Chen, Y. (TU Delft Coastal Engineering; Hohai University)
Yao, P. (TU Delft Coastal Engineering)
Su, M. (TU Delft Coastal Engineering)

2016-03-01

The effective roughness height is an important parameter in coastal sediment transport models. It has been extensively investigated in the past but few research results are related to the high-concentrated flows which often occur in a silty coast. A series of experiments has been carried out in a wave-current flume with silt-sized sediment bed. The mean velocity profiles were measured under different combined wave-current conditions. The effective roughness heights were calculated based on the curve fitting of measured velocity profiles by following the velocity profile model of You (1994). The accuracy of three empirical models, namely, Grant and Madsen (1982), Li and Amos (1998) and You (1996) was examined with the 'measured' effective roughness heights. The results show that all the models are not much accurate for the high-concentrated flows, particularly in the case with a relatively small sediment size. Therefore, cautions should be taken when applying those models in the silty coast, particularly during the extreme events.

Bed resistance
Sediment transport model
Silty coast

http://resolver.tudelft.nl/uuid:45d3dd73-f662-4e1f-90b3-7f17bf80d5be

https://doi.org/10.2112/SI75-011.1

0749-0208

Journal of Coastal Research: an international forum for the Littoral Sciences, 1 (75), 53-57

14th International Coastal Symposium, 2016-03-06 → 2016-03-11, Sydney, Australia

Institutional Repository

journal article

© 2016 Jiayu Fang, Y. Chen, P. Yao, M. Su