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| Numerical analysis of hydrodynamic characteristics in confluence of mainstream with a tributary in a river-type reservoir |
| LU Jianyu1, MAO Jingqiao2*, GONG Yiqing2,3, CAI Haibin2, CAO Qing2, DAI Huichao2, YAN Jie4 |
| 1. East China Branch of State Grid Corporation, Shanghai 200120, China; 2. College of Water Conservancy and Hydropower Enginee-ring, Hohai University, Nanjing, Jiangsu 210098, China; 3. School of Engineering, Cardiff University, Cardiff CF24 3AA, United Kingdom; 4. Northwest Electric Power Design Institute Co., Ltd. of China Power Engineering Consulting Group, Xi′an, Shaanxi 710075, China |
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Abstract Based on the geometry of the confluence of the mainstream with a tributary and their hydrological conditions in a typical river-type reservoir, a three-dimensional hydrodynamic model was developed to investigate the impact of intersectional angle of the tributary with the mainstream on hydrodynamic characteristics in the confluence. Five scenarios were focused in terms of 30? 60? 90? 120? and 150?intersectional angles, respectively. The results illustrate that there is always a high concentration region of turbulent kinetic energy at these intersectional angles, and a positive correlation exist between the turbulent kinetic energy and the angle, that is, both the high turbulent kinetic energy region size and value increase significantly with increasing angle. The maximum bed shear stress always decreases from the confluence to the upstream of the tributary at various intersectional angles. If the angle is less than 90? the coefficient of variation of stream velocity increases first and then decreases from the confluence to the upstream; otherwise the coefficient decreases steadily towards the upstream. Additionally, if the angle is less than 90? both the bed shear stress and the coefficient of variation exhibit a negative correlation with the angle, or a positive correlation exists between them.
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Received: 29 December 2017
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