Faculty of Civil Engineering, Architecture and Geodesy ; Faculty of Electrical Engineering, Mechanical Engineering and Naval Architecture
Abstract
For the purpose of studying 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 one-dimensional (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 axis, is added. Accordingly, 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 the description of the used numerical formulation (based on the method of characteristics), a numerical example is also presented in the support of the given statements
