Search results for "Large-scale roughne"

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Flow resistance in gravel-bed channels with large-scale roughness

2003

A previously published mixing length (ML) model for evaluating the Darcy–Weisbach friction factor for a large-scale roughness condition (depth to sediment height ratio ranging from 1 to 4) is briefly reviewed and modified (MML). Then the MML model and a modified drag (MD) model are experimentally tested using laboratory measurements carried out for gravel-bed channels and large-scale roughness condition. This analysis showed that the MML gives accurate estimates of the Darcy–Weisbach coefficient and for Froude number values greater than 0·5 the MML model coincides with the ML one. Testing of the MD model shows limited accuracy in estimating flow resistance. Finally, the MML and MD models are com…

Flow resistanceScale (ratio)Depth to sediment height ratioGeography Planning and DevelopmentLarge-scale roughnessSurface finishMechanicsScale factorsymbols.namesakeFlow resistanceDragGravel-bed channelEarth and Planetary Sciences (miscellaneous)ExponentFroude numbersymbolsSettore AGR/08 - Idraulica Agraria E Sistemazioni Idraulico-ForestaliGeotechnical engineeringConstant (mathematics)Earth-Surface ProcessesMathematicsEarth Surface Processes and Landforms
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Discussion on 'Estimating depth-averaged velocities in rough channels'

2002

In this short communication the four estimate criteria of the depth-averaged local velocity proposed by Byrd et al. (Earth Surface Processes and Landforms, 2000, Vol. 25, pp. 167-173) are compared both with the three-point method of Bathurst and with the average velocity obtained by integrating the velocity profile (FPa2) suggested by Ferro and Pecoraro (Water Resources Research, 2000, vol. 36, pp. 2761-2770). The comparison was carried out using 84 velocity profiles measured by an acoustic Doppler velocimeter in a rectangular flume with a gravel bed. Copyright © 2002 John Wiley and Sons, Ltd.

geographygeography.geographical_feature_categoryLandformDepth averagedGeography Planning and DevelopmentEarth surfaceFlumeGravel bedRiemann averageVelocity profileEarth and Planetary Sciences (miscellaneous)Large-scale roughneSettore AGR/08 - Idraulica Agraria E Sistemazioni Idraulico-ForestaliGeotechnical engineeringAcoustic Doppler velocimetryGeomorphologyGeologyEarth-Surface ProcessesEarth Surface Processes and Landforms
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