Author(s): A. Shakibaeinia; M. R. M. Tabatabai; A. R. Zarrati
Linked Author(s): Amir Reza Zarrati
Keywords: Channel confluences; Flow structure; Free surface; Flow separation; 3Dnumerical modeling
Abstract: Channel confluences are common features in river systems and water networks. Having a profound knowledge of flow structure in channel confluences is important for engineering purposes. Extensive laboratory, field and numerical studies have been conducted to clarify the characteristics of the complex flow structure in the confluences. Free surface elevation, velocity field and flow separation in the confluence are the features which have mostly been investigated by researchers. However, a comprehensive three dimensional numerical study of the flow characteristics under different confluence angles and discharge ratios has not been reported yet, and hence suggested empirical equations for flow characteristics in river confluences can not be generalized to real engineering problems. This study aims to investigate common features of flow in the channel confluences in a wide range of conditions using a well verified 3D numerical model. For this purpose, the numerical model was applied to the channel confluence with different discharge ratios, confluence angles. The results have been validated by some experimental data. Statistical analysis was then applied to obtain relationships between free surface variations, velocity field and flow separation in the channel confluences with different confluence angles, discharge ratios and Froude number values. These relationships may come into practice to study river confluences in engineering designs.
Year: 2009