Numerical And Experimental Study On The Hydraulic Characteristics Of Spillway

With the construction of high-head water power stations, the flood discharge of a spillway is larger and larger and its design is becoming more difficulty, so it is very important to study on the hydraulic characteristics of a spillway. Based on the existing research results, it is researched in this dissertation that the hydraulic characteristics of spillway such as water surface line, the law of pressure distribution, velocity distribution and flow pattern with the methods of theory and experiment including classical hydraulics computation, numerical simulation of turbulent flow and physical model test. The main contents and conclusions are as follows:1 Based on the theory of classical hydraulics, a visual basic program is developed for computing the hydraulic characteristics of the chute and another program for computing the distorted flip bucket. The results may be displayed by means of graphic and can be output to a text file. 2 With the k-εmodel of unsteady flow and the VOF method for tracking the free surface of water flow, the chute flows of spillway is simulated with a 3-D numerical model of turbulent flows. After the simulating computation, the hydraulic characteristics, such as the water surface lines, the pressure distributions and flow patterns of the chute flows are acquired. The results are also compared with that of VB program as well as the physical model test. The results of those three methods are in accord well with each other.3 The physical model research of the spillway is completed by combining the research together with a real engineering project spillway of Sanbanxi. In the experiments, the measurements of the water surface line, pressure, velocities of the chute and the distorted flip bucket flows were completed. The influences of different flip bucket on downriver tail water and scouring of the river bed are investigated in the experiments. The flip buckets are adjusted with the conditions of downriver, and an optimistic flip bucket is chosen from tens of ones at last.By means of the method of experiments and computation, the problem of roughness dissimilarity in model test is discussed. The research shows that when the deviation of model water depth from that of the prototype is in the permission of the technical specification, the test allows of eliminating the process of roughness-amending.