engleski

Numerical analysis of hysteresis in rating curves for open channel flow

For the purpose of study the hysteresis in rating curves for unsteady flow regime in open channels, a numerical analysis of water wave propagation is performed by a numerical integration of 1D Saint- Venant differential equations. By applying two different boundary conditions, which are specified as the time change in water level h at the upstream boundary of the flow domain, it is shown that the downstream rating curves can obtain the same shapes in the Q-h plane. However, to emphasize the expected difference in rating curves, a third, time axes, is added. Accordantly, the rating curves obtain a spatial shape from which the dynamics of evolution in the relation between the stage h and related discharge Q can be evidenced. Apart from describing the used numerical formulation (based on the method of characteristics), to support the given statement ; a numerical example is also presented.

rating curve; Saint Venant equations; open channel flow; water wave propagation

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