The author establishes the exact boundary observability of unsteady supercritical flows in a tree-like network of open canals with general topology. An implicit duality between the exact boundary controllability and t...The author establishes the exact boundary observability of unsteady supercritical flows in a tree-like network of open canals with general topology. An implicit duality between the exact boundary controllability and the exact boundary observability is also given for unsteady supercritical flows.展开更多
The relationship between the automatic control method and the stability of the open canal is studied by means of numerical simulation of unsteady flow in an open canal under different methods of control. It is found t...The relationship between the automatic control method and the stability of the open canal is studied by means of numerical simulation of unsteady flow in an open canal under different methods of control. It is found the Proportional-Proportional plus Reset （P＋PR） control is more reliable than the Linear Quadratic Regulator （LQR） control. Moreover, for the P＋PR control, the hydraulic response of the constant volume method of operation is better than that of the constant downstream depth method in the type of centrally controlled canal. Therefore, an appropriate flow change rate should be chosen instead of shortening the pool length to reach an acceptable drawdown rate. For the canal with a bottom width of 40 m, side slope of 3, Manning n of 0.015, bottom slope of 0.000 04, and design flow of 600 m3/s, the pool length of more than 30 km can provide acceptable drawdown rates of 0.2 m/h when a proper flow change rate is chosen.展开更多
文摘The author establishes the exact boundary observability of unsteady supercritical flows in a tree-like network of open canals with general topology. An implicit duality between the exact boundary controllability and the exact boundary observability is also given for unsteady supercritical flows.
基金Supported by the National Natural Science Foundation of China (51039007, 50979076)the National Basic Research Program of China (973 Program) (2010CB428802)the Open Research Fund of Key Laboratory for Water Requirement and Regulation, Ministry of Agriculture (CWRR200901)
文摘The relationship between the automatic control method and the stability of the open canal is studied by means of numerical simulation of unsteady flow in an open canal under different methods of control. It is found the Proportional-Proportional plus Reset （P＋PR） control is more reliable than the Linear Quadratic Regulator （LQR） control. Moreover, for the P＋PR control, the hydraulic response of the constant volume method of operation is better than that of the constant downstream depth method in the type of centrally controlled canal. Therefore, an appropriate flow change rate should be chosen instead of shortening the pool length to reach an acceptable drawdown rate. For the canal with a bottom width of 40 m, side slope of 3, Manning n of 0.015, bottom slope of 0.000 04, and design flow of 600 m3/s, the pool length of more than 30 km can provide acceptable drawdown rates of 0.2 m/h when a proper flow change rate is chosen.
