Two-Dimensional Numerical Model Of Sediment Density Current And Its Application In The Liujiaxia Reservoir

On the one hand, the sediment density current often does a great harm to the reservoir, and causes a big loss of reservoir's storage capacity or makes reservoir severe deposition; on the other hand, sediment outflow by density current is an effective measure to mitigate sedimentation. It is necessary to study on the sediment density current.After a comprehensive review on the study of sediment density current in the recent several decades, a set of differential equations for 2-D density current under double-layer computational mode is established. By simplifying th. set of equations, a 2-D numerical simulation of sediment density current and sediment outflow has been made in the Liujiaxia reservoir in the Yellow River basin, and the result is reasonable.The thesis' main studies and achievements are as follows:1. Under the assumption of double-layer computational mode, the governing equations for the horizontal 2-D stratified density current is derived by integrating the 3-D fundamental equations along the flow depth.2. By using the present accomplishment, the elementary equations are turned into model equations on which the numerical model is based.3. The finite volume method is used to disperse the differential equations.4. The numerical model is applied to the Liujiaxia reservoir, and the simulated results show a good agreement with the measured data. In addition, the application of the present model to the "Design of new sediment sluice at the Taohe mouth in the Liujiaxia reservoir" supports the experimental results conducted by the Department of Sediment Research, IWHR.The sediment density current is very complicated. The contributions by this thesis supply a good basis for further study on the density current. So it has a practical value.