摘要
为设计出1种含有涡流发生器的新型试验尾水管,对涡流发生器的机理进行一定的研究,并结合尾水管的工作原理,进行计算模拟和试验验证.根据尾水管的几何特征,运用壁面函数法建立全流道结构网格,用SST模型对其进行数值计算,分别以涡产生截面和涡开始发展截面作为涡流发生器叶片的安装截面,先后模拟了其55种不同工况下的水流特性.同时计算出尾水管各工况下的能量恢复系数,找出能使其能量恢复系数提高最大的安装方法.研究结果表明:以15°夹角于尾水管涡开始形成截面,对涡方式安装2对涡流发生器,且涡流发生器的安装截面在尾水管内部涡开始形成的位置.利用此安装方法进行试验验证,测量出试验尾水管的能量恢复系数提高了3.2个百分点,同时,提出了涡流发生器的安装截面为尾水管内部涡流开始形成的截面.为在建和改建水电站提供了一定的依据.
In order to develop a new type of draft tube with vortex-generators,the working mechanism of vortex-generators was analyzed in some extent,then a series of experimental model draft tubes with vortex-generators were designed by combination with the theory of draft tube; finally,verifying simulations and experiments were conducted on those models. In accordance with geometrical characteristics of the model draft tube,a structured mesh was generated by considering the near-wall function. The share stress transport( SST) model was used in the turbulent flow simulation. The blades of vortexgenerator were installed between two sections in the tube,one is the section where a vortex starts to be generated and the other is the section where the vortex begins to be developed,then 55 different working conditions were simulated. Finally,energy recovery coefficients were calculated,and the optimum blade installation was identified. It was shown that two pairs of counter rotating vortex-generators should be installed in the section where a vortex starts is generated and the angle between the generator and the draft tube center line should keep being 15°. A conforming experiment was conducted under this installation scheme,and 3. 2% improvement in energy recovery coefficient have been observed.This suggests that the position where vertex-generators are installed is the section where a vortex starts to occur. This proposal can be useful to hydropower stations being constructed and those being refurbished.
出处
《排灌机械工程学报》
EI
北大核心
2013年第9期783-787,共5页
Journal of Drainage and Irrigation Machinery Engineering
基金
国家自然科学基金资助项目(51076041)
关键词
涡流发生器
尾水管
能量恢复系数
SST模型
数值计算
vortex-generators
draft tube
energy recovery factor
SST model
numerical calculation
