INCEPTION OF SALTATION MODE OF SEDIMENT TRANSPORT


Abstract eng:
The bed load transport usually occurs in three consecutive modes: rolling, saltation, and suspension. The start of rolling motion is investigated widely, and different models are constructed and calibrated using available experiments. There are available few experiments and models for threshold between rolling and saltation. Herein the threshold of saltation in turbulent flow was determined and presented in common variables introduced by Shields (1936). The additional dimensionless parameter characterizing the bed surface formation was introduced. For the condition of the threshold there was chosen the equality of the submerged gravitational force and the lift force on a bed particle. For the low-studied shear induced lift force there were used data on well studied Magnus force on a rotating ball moving translationally in calm water. The critical shear stress as function of bed particle Reynolds number was determined analytically and reported in graphical form for different values of the bed parameter. The obtained results agree with available experiments on saltation start.

Contributors:
Publisher:
Institute of Thermomechanics AS CR, v.v.i., Brno
Conference Title:
Conference Title:
Engineering Mechanics 2008
Conference Venue:
Svratka (CZ)
Conference Dates:
2008-05-12 / 2008-05-15
Rights:
Text je chráněný podle autorského zákona č. 121/2000 Sb.



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 Record created 2014-11-13, last modified 2014-11-18


Original version of the author's contribution as presented on CD, , page 418. :
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