高水头泄洪洞掺气设施研究

发布时间：2018-05-09 20:33

  本文选题：泄洪洞 + 模型试验　； 参考：《长江科学院》2014年硕士论文

【摘要】：随着坝工技术的发展,在高山峡谷所建的高坝,往往具有水头高、落差大、泄洪功率大等特点,由此可能引发的空蚀问题日益突出。相比于优化体型、降低过流面不平整度和抗空蚀材料的运用,掺气设施的设置是一种比较有效的减蚀措施。论文在广泛调研的基础上,以乌东德水电站3#泄洪洞明流段的1：30单体水工模型为背景,采用物理模型试验和数值模拟相结合的方法,对掺气设施的水力特性进行了研究,取得了以下成果： (1)通过试验观测了泄洪洞明流段不设掺气设施条件下的过流形态、沿程水面线、压力特性和水流空化特性,在此基础上拟定了三种掺气设施方案的布置位置和体型尺寸,并进行了掺气减蚀设施试验研究。 (2)试验结果表明,泄洪洞明流段曲线连接段及其以下流道的断面水流平均流速超过30m/s。底板沿程压力整体变化平缓,但曲线连接段的底板压力较低,水流空化数低于0.3,需采取掺气减蚀措施进行保护。根据测量结果,设计了三种方案的掺气设施位置和体型尺寸,并进行了相应的掺气减蚀效果验证试验研究。综合比较三种方案的掺气效果,推荐使用方案Ⅲ的掺气坎为泄洪洞底部水流掺气。 (3)在模型试验的基础上建立泄洪洞明流段三维模型,采用六面体结构化网格对整个计算区域进行疏密有别的网格划分,并以模型试验结果率定数值模拟的边界条件。 (4)采用标准κ-ε模型和VOF模型及欧拉模型对泄洪洞及掺气设施水力特性进行了三维数值模拟计算。主要计算了自由水面、掺气设施水力特性和空腔特性及坎后沿程渠底板中心线的掺气浓度。计算结果表明,VOF模型和欧拉模型可以在一定程度上模拟掺气设施水力特性和空腔形态等水力参数。总体而言,在对泄洪洞掺气设施的数值模拟方面,欧拉模型在一定程度上比VOF模型有更好的模拟精度。 (5)利用数值模拟可提高水利设计效率和节省费用,并为模型试验提供前期预测和指导，，同时其结果可以作为模型试验补充和完善的依据，本文所采用的数值模拟方法及研究结果可供类似工程的研究参考。
[Abstract]:With the development of dam construction technology, high dams built in high mountain canyons often have the characteristics of high water head, large drop and large flood discharge power. Compared with optimizing the shape, reducing the roughness of flow surface and the application of anti-cavitation material, the installation of aeration equipment is an effective corrosion reduction measure. On the basis of extensive investigation and research, the hydraulic characteristics of aeration facilities are studied by using the physical model test and numerical simulation under the background of 1:30 single hydraulic model in the open flow section of the flood discharge tunnel of the Udongde Hydropower Station, and the physical model test and numerical simulation are used to study the hydraulic characteristics of the aeration facility. The following results were achieved: 1) the flow patterns, water surface profile, pressure characteristics and cavitation characteristics of flow in the open flow section of flood discharge tunnel without aeration facilities are observed experimentally. On the basis of these observations, the location and size of three aeration facilities are worked out. The experimental study on the aeration corrosion reduction facility is also carried out. 2) the experimental results show that the average flow velocity of the section of the open flow section of the flood discharge tunnel is more than 30 m / s. The pressure of the bottom plate changes slowly along the course, but the bottom pressure of the curve joint section is lower and the cavitation number of the flow is less than 0.3, so it is necessary to take aeration erosion reduction measures to protect the bottom plate. According to the measurement results, the position and size of the aeration facilities were designed, and the experimental study on the effect of the aeration corrosion reduction was carried out. By comparing the aeration effect of the three schemes, it is recommended that the aerator of scheme 鈪

本文编号：1867324