非对称复式断面明渠水流特性试验与数值模拟

采用三维超声测速仪对非对称复式断面明渠水流流场特性进行试验研究,采用L-Y雷诺应力模型对水面和固壁边界条件进行有效地处理,结合混合有限分析法数值模拟了复式断面明渠二次流流动,和实验资料的对比验证了数值计算和边界处理技术的合理可靠性.进一步分析复式断面明渠二次流运动的流动结构和特性,得到复式断面明渠流动中的二次流分布速度矢量分布、主流流速等值线及典型断面沿水深的主流流速分布,发现自由水面上的主流速度存在速度下降现象,二次流产生最明显的位置在明渠主槽与浅滩的接合部.

Experimental and numerical study on behavior of flow in a unsymmetrical compound channel

3-D MicroADV was used to test the flow in unsymmetrical compound channel.The Launder and Ying algebraic Reynolds stress turbulent model with hybrid finite analytical method was applied to simulate the secondary current in the compound channel.The wall function was adopted such that a resultant stream-wise velocity was expressed by a local friction velocity at a first grid point to the wall of the computation domain.The expression for the dissipation rate given by Rodi at a first grid point of the surface was adopted.The agreement with the experimental data showed that the model and calculate method were available.The secondary current velocity in the cross section and main current velocity distribution along the depth of the water in representative position were indicated as a result.It showed that there was a velocity-dip of the main current flow near the water surface.The secondary currents were generated near the corners and sidewalls of channel.