Numerical analysis of flow separation zone in a confluent meander bend channel

• Published in: Journal of hydrodynamics. Series B 2017-08, Vol.29 (4), p.716-723
• Main Author: 隋斌 黄社华
• Format: Article
• Language: English
• Subjects: discharge ratio; junction angle; Large eddy simulation (LES); quasi-2-D; separation zone; 分离区; 弯道水流; 数值分析; 数值模拟; 水流流态; 湍流特征; 相对长度; 计算结果
• ISSN: 1001-6058
• DOI: 10.1016/S1001-6058(16)60783-7

The flow pattern in the confluent meander bend channel under the conditions of different discharge ratios and junction angles is numerically simulated by means of the large eddy simulation（LES）, and the characteristics of the flow separation zone are analyzed. Numerical results are well validated by experimental data with a good agreement. Analysis of the vertical confinement shows that the turbulence within the separation zone can be characterized as quasi-2-D. Details of the separation zone characteristics are revealed as shown by mean velocity isolines. According to the analysis of numerical results, the length and the width of the separation zone generally increase with the increase of the discharge ratio and the junction angle. However, the width of the separation zone keeps substantially constant when the junction angle increases from 60 o to90o. The dimensionless shape of the separation zone is nearly the same for three discharge ratios and three junction angles. The formulas of the relative width and the relative length of the separation zone are obtained by means of the polynomial fit method.