Numerical Study on Influence of Oriented Groin Angle on Hydraulic Characteristics of Curved Water Flow

摘要

After the spur dike is laid in the curved channel, the water flow characteristics are significantly different with the angle of the installation. To explore this problem, by using MIKE3 FM within 60° bend channel model of single spur dike to choose different angle to the three-dimensional numerical simulation of flow around the situation and the different angle, corner the flow field structure and surface morphology analysis, such as flow is discussed in this paper. The results show that: When the angle of the spur dike is increased, the flow field structure and surface morphology around the spur dike will change. Mainly in the area of the recirculation zone after the dam, first increase and then decrease. The transverse gradient of the water surface in the upstream area increases first and then decreases. The transverse gradient of the water surface in the downstream area decreases first and then increases. Spur dike is a commonly used building in revetment works and waterway remediation, which has the functions of protecting bank embankment, bunching water to channel, improving waterway conditions, maintaining river facies and guaranteeing diversification of aquatic environment. At present, the analysis of the characteristics of the water flow around the spur dike mainly through the river model test and numerical simulation. Kang used LES (large eddy simulation) method to study and analyze the three-dimensional flow field near the rectangular spur dike in the straight channel water tank, and also analyzed the water flow structure before and after the spur dike. Outllon et al. used a standard k ε-model to simulate Holtz's spur dike test and calculate the relative length of recirculation zone. Akahori et al. used a non-static pressure three-dimensional model to simulate the flow around the spur tank test of Muneta et al. Domestic Li Zhiqin, Li Hong et al used a standard k ε-model coupled with the control volume method to simulate the free water surface around the spur dike, and the results are basically consistent with the measured values. In this paper, the MIKE3 FM model is used to simulate the flow recirculation characteristics of continuous non-submerged spur dike. The calculation results are in good agreement with the experimental results of Han et al. On this basis, the three-dimensional model is used to study the influence of different angles of non-submerged straight spur dike on the flow field and surface morphology around the curve in the 60° curved water flow. The research results can provide reference for channel Regulation and spur design and construction which have important theoretical value and practical engineering significance.