Experiment And Numerical Simulation Study On Hydrodynamics Characteristics Of Lashan Flood Diversion Engineering In Jinan

The Lashan River diversion engineering is the key project of Xiaoqiao river’s mainstream management and the important content of flood control system construction in Jinan city. This paper is the research on some practical problems of Lashan River diversion engineering in Jinan to build physical model, and set up hydrodynamic models including one-dimensional river network model and two-dimensional surface runoff model, and also studies the flow characteristics of the inverted siphon. The research methods of this paper combine the physical model and the numerical simulation to study the water flow, water level, local flow state and the discharge capacity of hydraulic structures in different frequency flood. The main research contents of this paper are as follows:(1) Hydraulic model tests. Building physical model according to the similarity theory and measuring the water level, discharge in different conditions, the physical model is Fixed bed and abnormal model that including model design, roughness test, selection of the parameter, result analysis, evaluation and so on.(2) Numerical simulation study on hydrodynamic characteristics. Developing the one-dimensional river model of Lashan River with MIKE11hydrological model and simulating the water level and the water flow of every cross-section, every moment in different conditions, the calculation results were in good agreement with the experiment data except in the inverted siphon.(3)Developing the two-dimensional surface model of Lashan River in different conditions with MIKE21hydrological model, some visual results including the flow field distribution and the water depth contours were obtained. The flow of the intersection of Dajiangou River and Lashan River is smooth and steady because of the cross-section designed, but the flow in the Jingfu Bridge is unsteady due to the sudden contractive cross-section that the scour on both sides is very serious, so that the protection of the both sides should be considered.(4) Through simulating the inverted siphon with Fluent software because of the Physical model cannot reflect the flow of inverted siphon directly, the flow capacity, the curvilinear water surface, the magnitude and distribution of the velocity and so on were obtained, in order to study the flow field distribution and the flow state directly.