Author(s)

K. K. KHATUA, K.C. PATRA, P. NAYAK & N. SAHOO

Abstract

Accurate estimation of discharge in any open channel depends on the suitable accounting of the resistance coefficients. The energy loss is influenced by the channel geometry and flow parameters, which are assumed to be lumped into a single value manifested in the form of resistance coefficients in terms of Manning's n, Chezy's C, and Darcy–Weisbach f. The flow structure for meandering channels is more complex as compared to that of straight channels due to its three-dimensional motion. Consequently, the use of design methods based on straight channels is inappropriate when applied to meandering channels and results in large errors when estimating the discharge. A series of experimental results are presented concerning stage–discharge–resistance relationships for meandering channels with rigid and smooth boundaries. Investigation concerning the loss of energy of flows for meandering channels in terms of variation of Chezy's C due to variation of sinuosity, geometry, and longitudinal slope are studied.A discharge predictive method for meandering channel is proposed that accounts for the variation of roughness with depth of flow in the channel. The performance of the model is evaluated and is found to compare well with other available models.

Keywords

Aspect ratio, bed slope, boundary shear, dimensional analysis, flow resistance, meandering channel, sinuosity, stage–discharge relationship