Author(s): K. K. Khatua, K. C. Patra & P. Nayak
During uniform flow in an open channel, the resistance is dependent on a
number of flow and geometrical parameters.
The usual practice in one
dimensional flow analysis is to select an appropriate value of roughness
coefficient for evaluating the carrying capacity of natural channel.
This value of
roughness is taken as uniform for the entire surface and for all depths of flow.
However, it is observed that the resistance coefficients for meandering channels
are found to vary with flow depths, aspect ratio, slope and sinuosity and are all
linked to the stage-discharge relationships.
Although much research has been
done on Manning’s n for straight channels, a last word has not been spoken on
the roughness values for meandering channels.
An investigation concerning the
variation of roughness coefficients for meandering channels with slope, sinuosity
and geometry are presented.
The loss of energy in terms of Darcy–Weisbach
coefficient f is evaluated.
A simple equation for roughness coefficient based on
dimensional analysis is modeled and tested with the recent experimental data.
The method gives discharge results that are quite comparable to that of the
observed values as well as with other published data.
aspect ratio, bed slope, boundary shear, Darcy–Weisbach coefficient,
dimensional analysis, meandering channel, flow resistance, Sinuosity (Sr), stagedischarge
The energy loss in a meandering channel is influenced by the channel and flow
parameters and is assumed to be lumped into a single value that is manifested in
the form of a single resistance coefficient.
Wrong estimation of resistance
coefficient can either underestimate or overestimate the discharge carrying
Size: 998 kb
Paper DOI: 10.2495/RM110191
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