Abstract
Traditional methods of measuring the profile of a scour hole or bed form have poor temporal resolution and may require the temporary cessation of the flow in order to be executed. These are undesirable characteristics since many hydraulic flows have unsteady water-sediment interfaces that can display considerable differences between their “dynamic” (flow on) and “static” (flow off) states. The present technical note discusses the application of planar laser sheet illumination to the erosion of a cohesionless granular bed due to a planar turbulent wall jet. The measurements allow for the quantitative study of the evolution of the bed in its earliest stages. In some cases an ephemeral bed form is observed to form prior to the development of the main bed form. Additionally, the measurements illustrate the oscillatory nature of the bed form under certain conditions. The experiments therefore demonstrate the great potential of this experimental technique for gaining previously inaccessible information on scour processes.
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Information
Published In
Journal of Hydraulic Engineering
Volume 135 • Issue 10 • October 2009
Pages: 852 - 856
Copyright
© 2009 ASCE.
History
Received: Jan 25, 2008
Accepted: Mar 23, 2009
Published online: Mar 25, 2009
Published in print: Oct 2009
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