【作者】 凡伟； 槐文信； 崔丹；

【Author】 FAN Wei,HUAI Wen-xin,CUI Dan State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University,Wuhan 430072, Guiyang Hydropower Investigation Design & Research Institute,CHECC,Guiyang 550081

【机构】 武汉大学水资源与水电工程科学国家重点实验室； 中国水电顾问集团贵阳勘测设计研究院；

【摘要】 为了研究河床形态对弯道水流特性的影响,本研究应用RNG k-ε模型对复式断面弯道进行了数值模拟分析。给出了水流特性在断面上的分布特点及其沿弯道的变化过程。模拟结果与前人对复式断面顺直河道和矩形断面弯道的水流特性对比分析,发现受台阶和弯道曲率的双重影响,弯道水流的纵向速度,二次流等相关水流特性明显不同于上述两种渠道水流的特性。另外,主槽底面剪切力沿着弯道不断增加,而滩地底面剪切力不断减小。基于动量平衡方程中各项在弯道断面上的分布分析,结果表明,横向压力梯度项和离心力项在弯道横向水流运动中起主导作用。对纵向水流的运动,动量平衡方程各项的作用是相当的。更多还原

【Abstract】 A 180°curved open channel with compound cross section is simulated with RNG k-εmodel to investigate the flow characteristics influenced by the bed topography.The distribution features in the cross section and variation along the bend of the flow characteristics,based on the simulation results,were given.Compared with the flow field of the straight channel with compound cross section and the curved channel with rectangular cross section,we can see that the distribution of velocity,secondary flow are evidently different from that in the two kinds of channel mentioned above,because it is deeply influenced by the bend curvature and the stage.In addition,the bed shear stress of main channel increases progressively along the bend,while the bed shear stress of the stage decreases.The analysis of momentum equation shows that the flow in transverse direction is fully dominated by the transverse pressure gradient and centrifugal force.While each term in the longitudinal momentum equation is the same order of the magnitude.更多还原