Numerical Simulation Of Three Dimensional Flow And Its Application In Hydraulic Engineering

With the rapid development of technology, there are great changes in modern hydraulics. Theoretical analysis, experimental research and numerical simulation become the main methods of hydraulics. And with the progress of computer technology, Computational Fluid Dynamics (CFD) is wildly used and recognized in hydraulic engineering.With the help of numerical simulation technology, several actual flows are computed by fluid software in this dissertation where part of the computer program is compiled by hand.Based on the characteristics of water-keeping weir, the mathematical model is set up and the flow field is simulated. The distribution of flow velocity and time-average pressure near the water-keeping weir is obtained, and the local head loss coefficient of the water-keeping weir is calculated with a successful solution of the water-air interface in two face flow.In the background of Cha Han Wu Su hydropower project, the flow field of the spillway tunnel is simulated. The discharge of the spillway tunnel and the pressure of the measuring points in gate slot which were compared with the test data are obtained. In addition, an analysis is given about the cavitations of the gate slot and the free-full flow of the spillway tunnel.The flow field of the PCCP pipeline is simulated, so the head loss and resistance coefficient are calculated which are consistent with the test data. Additionally, other pipelines of different diameter are also simulated, and the resistance coefficient's law along with the diameter is carried out.A mathematical model of La Xi Wa arch dam including reservoir area and cushion pool is set up and then simulated. The discharge capacity of crest outlet and bottom outlet is calculated, and the distribution of time-average pressure of the crest outlet, bottom outlet and cushion pool is obtained.