Open-Channel Surge Simulation By Digital Computer

The equations of motion for unsteady gradually-varied flow in open channels are expressed in a finite-difference form suitable for programming on a high-speed digital computer. The staggered-net scheme introduced by Stoker is expanded to be applicable to a system of N interconnected channels, with each of their ends subject to one of the following boundary conditions: discharge hydrograph, stage hydrograph, stage-discharge relationship, dead end or junction of channels. The theory and computer program are tested and compared with existing experimental results corresponding to the following situations: (1) Flood hydrograph in circular channel; (2) power-load rejection in headrace of trapezoidal canal; (3) power-load acceptance in tailrace of rectangular model channel; and (4) tidal (stage hydrograph) in rectangular model estuary. Because of good correlation between simulated and experimental results in all four instances and the ease of coding various problems, the staggered scheme of Stoker is strongly recommended for practicing engineers.