节点文献
平板闸门小开度水流数值模拟及闸门槽水流特性研究
【作者】 黄海艳；
【导师】 王海军；
【作者基本信息】 昆明理工大学 ， 水利水电工程， 2011， 硕士
【摘要】 随着我国水利水电事业的发展,大量高坝大库水电工程得到兴建,高水头下的泄水建筑物水流流速一般都超过30m/s,高速水流易使泄水建筑物表面发生空蚀,而门槽附近也是一个容易遭受空蚀的区域,本文在总结前人研究的基础上,采用标准的κ-ε紊流模型,对二维门槽的流速场、压强分布等进行模拟计算。建立隧洞闸门小开度的三维数学模型,计算了三维门槽的速度场与边壁的压力分布,得到了隧洞洞身段顶部中轴线、底板中轴线、侧墙中线以及闸后中轴线压力、流速场、紊动能和紊动能耗散率等的分布规律,本文所做的主要工作有如下几个方面：采用标准的κ-ε紊流模型,首先对前人的试验结果进行模拟,试验值与计算值比较结果基本吻合,得出所选择数学模型和计算方法的可靠性和正确性,然后模拟了门槽内漩涡的形成过程、不同宽深比门槽的流场及紊动能和紊动能耗散率的分布特点；数值计算了不同宽深比、错距比、圆角比、斜坡比的门槽压强分布特点,通过研究分析,得出较优的门槽体型参数,从而有效地减免门槽空化；建立隧洞闸门小开度的数学模型,采用RNGk-s模型计算了隧洞有压段及闸后明渠段的三维流场,VOF水-气界面追踪方法来处理闸后复杂的自由液面,模拟了三维门槽水流的速度场与边壁的压力分布,得到了隧洞洞身段顶部中轴线、底板中轴线、侧墙中线以及闸后中轴线压力、流速场、紊动能和紊动能耗散率等的分布规律,数值计算结果与试验所测结果进行对比分析,两者基本吻合。
【Abstract】 With the development of hydropower engineering in our country, a lot of hydropower projects with high dams and large reservoirs have been constructed. However, the flow velocity of the outlet structures with the high water head is often as high as 30m/s or more, easy to cause cavitation on the surface of discharge structure, especially for the place of the gate slot. Based on the former research, this paper used a standard k-εturbulence model to simulate and calculate the flow velocity field of two-dimensional gate slot and the pressure distribution, established a three-dimensional mathematical model for the deep hole gate with a small opening degree, calculated the velocity field and pressure distribution of the three-dimensional gate slot, and got the distribution rate of the pressure, velocity field, turbulence energy,turbulent energy dissipation rate and so on, with the tunnel’s top axis, bottom axis, side axis and the axis behind the gate. The major work in this paper can be composed of three parts as follows:This paper simulated previous measured results by RNG k-εturbulence model, and the calculated value was consistent with measured value, which showed that the mathematical model and calculation method are reliability and validity. Then, the formation of vortex in gate slot, velocity field, turbulent energy and its dissipation rate of different width to depth ratio were simulated. The pressure distribution features of gate slots, with different width to depth ratio, stagger ratio, fillet ratio and slope ratio, were calculated. The excellent gate slot shape parameter was obtained based on the research and analysis, and then reduced the cavitation of gate slot effectively.A mathematical model of the deep hole tunnel gate in small opening degree was established, three-dimensional flow field of tunnel pressure segment and open channel after gate was simulated by RNG k-εmodel. Complex free surface after gate has been processed with VOF method, velocity field and boundary pressure distribution of three-dimensional gate slot flow was simulated to get the distribution rate of the pressure, velocity field, turbulence energy, turbulent energy dissipation rate and so on, with the tunnel’s top axis, bottom axis, side axis and the axis behind the gate. The calculated results were found to be basically consistent with the measured after a series of analysis and companson.