Comments on “turbulent velocity profile in fully-developed open channel flows”

2008 ◽  
Vol 8 (4) ◽  
pp. 389-394 ◽  
Author(s):  
Rafik Absi
Keyword(s):  
Velocity Profile ◽  
Open Channel ◽  
Channel Flows ◽  
Turbulent Velocity ◽  
Open Channel Flows

Turbulent velocity profile in fully-developed open channel flows

2008 ◽  
Vol 8 (1) ◽  
pp. 1-17 ◽  
Author(s):  
Hossein Bonakdari ◽  
Frédérique Larrarte ◽  
Laurent Lassabatere ◽  
Claude Joannis
Keyword(s):  
Velocity Profile ◽  
Open Channel ◽  
Channel Flows ◽  
Turbulent Velocity ◽  
Open Channel Flows

Friction velocity and power law velocity profile in smooth and rough shallow open channel flows

2002 ◽  
Vol 29 (2) ◽  
pp. 256-266 ◽  
Author(s):  
R Balachandar ◽  
D Blakely ◽  
J Bugg
Keyword(s):  
Boundary Layer ◽  
Velocity Profile ◽  
Froude Number ◽  
Power Law ◽  
Friction Velocity ◽  
Open Channel ◽  
Rough Surfaces ◽  
Channel Flows ◽  
Open Channel Flows ◽  
Log Law

This paper examines the mean velocity profiles in shallow, turbulent open channel flows. Velocity measurements were carried out in flows over smooth and rough beds using a laser-Doppler anemometer. One set of profiles, composed of 29 velocity distributions, was obtained in flows over a polished smooth aluminum plate. Three sets of profiles were obtained in flows over rough surfaces. The rough surfaces were formed by two sizes of sand grains and a wire mesh. The flow conditions over the rough surface are in the transitional roughness state. The measurements were obtained along the centerline of the flume at three different Froude numbers (Fr ~ 0.3, 0.8, 1.0). The lowest Froude number was selected to obtain data in the range of most other open channel testing programs and to represent a low subcritical Froude number. For each surface, the Reynolds number based on the boundary layer momentum thickness was varied from about 600 to 3000. In view of the recent questions concerning the applicability of the log-law and the debate regarding log-law versus power law, the turbulent inner region of the boundary layer is inspected. The fit of one type of power law for shallow flows over a smooth surface is considered. The appropriateness of extending this law to flows over rough surfaces is also examined. Alternate methods for determining the friction velocity of flows over smooth and rough surfaces are considered and compared with standard methods currently in use.Key words: power law, open channel flow, velocity profile, surface roughness.

scholarly journals Re-examining log law velocity profile in smooth open channel flows

2020 ◽  
Vol 20 (4) ◽  
pp. 953-986 ◽  
Author(s):  
Nadeeka S. Miguntanna ◽  
Hamish Moses ◽  
Muttucumaru Sivakumar ◽  
Shu-Qing Yang ◽  
Keith James Enever ◽  
...  
Keyword(s):  
Velocity Profile ◽  
Open Channel ◽  
Channel Flows ◽  
Open Channel Flows ◽  
Log Law
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