Author(s): K. Shiono; Y. Muto; D.W. Knight; A.F.L. Hyde

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Abstract: An investigation of energy losses due to boundary friction, secondary flow, turbulence, expansions and contractions in meandering compound channels with overbank flow is described.The compound meandering channel was divided into three sub-areas, namely the main channel below the bankfull level, the meander belt width above the bankfull level and a region outside the meander belt above the bankfull level, and turbulence data obtained by a Laser Doppler anemometer system.The energy loss due to the shear stress on the horizontal plane at the bankfull level was estimated using the measured Reynolds stresses and sectional averaged velocity, and the energy loss due to secondary flow below the bankfull level was then estimated.Both energy losses were found to make a significant contribution to the total energy loss in the lower layer for shallow overbank flow.The energy losses due to the contraction and expansion in the meander belt were evaluated and found to be a significant component of the total energy loss in the upper layer for high overbank flow, but less so for shallow overbank flow.The energy losses due to bed friction and shear at the bank full level were found to be significant for shallow overbank flow.

DOI: https://doi.org/10.1080/00221689909498521

Year: 1999