阶梯溢流坝滑行水流掺气过程的大涡模拟  

Large eddy simulation of air-entrainment process in skimming flow over a stepped spillway

作　　者：张建波[1] 詹杰民[1] 龚也君[1] 

机构地区：[1]中山大学工学院,广东广州510275

出　　处：《广西大学学报（自然科学版）》2017年第4期1572-1580,共9页Journal of Guangxi University（Natural Science Edition）

基　　金：广东省协同创新与平台环境建设专项项目(2014B090904066);广东省公益研究与能力建设专项项目(2015A020216008;2016A010104006)

摘　　要：阶梯滑行水流具有较强的紊动特征和复杂的水—气自由面,其数值模拟研究具有较高的难度。文中采用数值模拟方法对阶梯溢流坝的溢流过程与滑行水流的掺气过程进行研究,并探讨其掺气机理。采用体积分数(VOF)多相流模型和大涡模拟(LES)方法,对坡度为2.5∶-1的阶梯溢流坝模型进行计算。结果表明,计算结果与实验结果较为吻合,数值模型可靠,且能够生动地模拟阶梯溢流过程和掺气过程。进一步分析得出结论:足够大的湍动能和涡结构发展是自由面变形继而发生自掺气的内部原因。Skimming flow over stepped spillway has strong turbulence characteristics and complex air-water interface,so that the relative numerical research is challenging. This study is trying to numerically investigate the overflow process,the self-aeration process of the skimming flow and the aeration mechanism. Based on the volume fraction（ VOF） multiphase flow model and the large eddy simulation（ LES） method,the stepped chute with a slope of 2. 5 ∶-1 is modeled. The results show that the calculated results are in good agreement with the experimental results. The numerical result reflects the overflow process and the air entrainment process vividly. Further analysis concludes that free surface deformation and the followed aeration occur once the turbulent kinetic energy is large enough to develop the vortex structure with the step length scale near the free surface.

关 键 词：大涡模拟 阶梯溢流坝 掺气 湍流 

分 类 号：TV652.1[水利工程—水利水电工程]