Depth-averaged flow in presence of submerged cylindrical elements


Huthoff, F. and Augustijn, D.C.M. and Hulscher, S.J.M.H. (2006) Depth-averaged flow in presence of submerged cylindrical elements. In: Rui M.L. Ferreira (Ed.), River flow 2006. Taylor & Francis, London, pp. 575-582. ISBN 9780415408158

[img] PDF
Restricted to UT campus only

Abstract:The hydraulic resistance of vegetation can play a major role in the hydrodynamics of rivers with extensive natural floodplains. Vegetation penetrates the flow field and thereby causes drag that, in addition to the flow resistance at the bed level, causes energy losses and slows down the flow. Here, these flow processes are studied in an idealized form by treating vegetation as cylindrical roughness elements with homogeneous geometrical dimensions. Based on scaling considerations of the forces involved, depth-averaged flow velocities within the resistance layer and in the free flowing layer above the roughness elements are estimated. This yields a new description of the overall average flow field, which is entirely determined by measurable geometrical boundaries. We tested the new relation against laboratory flume experiments and found very good agreement (R2 =0.98). The new description even showed realistic results when the depth of flow is of similar size as the height of the roughness elements themselves. This result demonstrates its superiority over commonly used wall-roughness methods.
Item Type:Book Section
Copyright:© 2006 Taylor & Francis
Engineering Technology (CTW)
Research Group:
Link to this item:
Export this item as:BibTeX
HTML Citation
Reference Manager


Repository Staff Only: item control page

Metis ID: 230610