Results 171 to 180 of about 363,183 (210)
Some of the next articles are maybe not open access.
Equivalent Roughness of Alluvial Bed
Journal of the Hydraulics Division, 1982The eguivalent roughness of a movable bed is considered. Relationships are given which can be used to determine the equivalent bed roughness from the bed material size and the bed-form dimensions. In the case of a plane bed the equivalent roughness is related to the D 9 0 of the bed material.
openaire +1 more source
Movable Bed Roughness in Alluvial Rivers
Journal of Hydraulic Engineering, 1999A method for the prediction of a movable bed roughness coefficient is proposed by relating the roughness parameter \iA to the nondimensional shear stress τ\u′\i\db/τ\i\dc\d5\d0 and the Froude number of flow. This relationship is tested with a large number of flume and field data from different sources, and also compared with other prediction methods ...
Weiming Wu, Sam S. Y. Wang
openaire +1 more source
Density Currents Dynamics over Rough Beds
Applied Mechanics and Materials, 2015Density currents are flows driven by density differences caused by suspended fine solid material, dissolved contents, temperature gradient or a combination of them. Reservoir sedimentation is often related to sediment transport by density currents. This sedimentation can block bottom outlets, reduce the capacity of reservoir and harms the dam power ...
Reza Nasrollahpour +4 more
openaire +1 more source
Influence of bed surface roughness on flow in rough-bed rivers
Riverbed surface roughness (or topography) modulates channel hydrodynamics, including the velocity and turbulence distributions, which underpin flood risk and sediment transport. Our recent research has presented the diversity of bed surface roughness found in bedrock and boulder-bed channels, prompting an investigation into the subsequent ...Robert Houseago +10 more
openaire +1 more source
Geometric bed roughness and the bed state storm cycle
Journal of Geophysical Research, 2011[1] Temporal variation in the geometric roughness of the mobile sandy seabed during wave forcing events is investigated as a function of bed state. The bed states include irregular ripples, cross ripples, linear transition ripples, and flat bed, each appearing repeatedly within a different range of wave energies, as part of the bed state storm cycle ...
openaire +1 more source
Roughness in Fixed-Bed Streams
2017The solid boundaries of a natural watercourse are usually composed of earth, sediments, and vegetation of different species, which together determine the resistance to the flow of water. From a hydraulic point of view, these parameters are treated as equivalent roughness.
openaire +1 more source
Turbulent oscillatory flow over rough beds
Journal of Fluid Mechanics, 1987Velocity measurements are presented for turbulent oscillatory flow over rough beds. Two components of velocity were measured with a laser-Doppler anemometer and the rough beds consisted of a single layer of sand, gravel or pebbles on a flat surface. Turbulence intensities showed significant variation during the course of the cycle.
openaire +1 more source
Bed roughness adjustments determined from fractal measurements of river-bed morphology
Journal of Hydrodynamics, 2018The flow resistance in rivers is an old and partly unsolved problem. In this study, the bed surface fractal dimension (BSFD) is used to describe the bed morphology, and combined with the bed roughness, a general model experiment is developed. The results show that there is a positive relationship between the BSFD and the bed roughness, which can be ...
Yin-jun Zhou +3 more
openaire +1 more source
Roughness of stable, armored gravel beds
Water Resources Research, 1993The grain roughness of stable armored beds that formed in a laboratory flume under a range of steady flow conditions on rounded, flat and angular gravel is analyzed. Gravel roughness geometry is determined from bed surface profiles and vertical photographs. These techniques have been employed in field situations.
openaire +1 more source