Backwater Computation for Transcritical River Flows
Publication: Journal of Hydraulic Engineering
Volume 122, Issue 12
Abstract
Analysis of the discrete equations for steady open-channel flows shows that the solution limit of the upstream backwater computation can be extended to Froude numbers exceeding one. An iterative method is proposed that allows for solution of either the momentum equation or the energy equation up to a limiting Froude number. The value of the limiting Froude number depends mainly on the friction losses and the size of the calculation interval, i.e., the distance between the cross sections. For the calculation of channels with rough beds and relatively small flow depths a typical value for the limiting Froude number is 1.5. To allow calculation for Froude numbers that exceed the limiting value, a reduction formula for the convective term is evaluated that ensures stability for the solution of the flow equations. The method is especially useful for transcritical flows in natural rivers where the flow oscillates between suband supercritical, and changing the direction of calculation would be impracticable.
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References
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Information
Published In
Journal of Hydraulic Engineering
Volume 122 • Issue 12 • December 1996
Pages: 745 - 748
Copyright
Copyright © 1996 American Society of Civil Engineers.
History
Published online: Dec 1, 1996
Published in print: Dec 1996
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