摘要
在环形涡轮叶栅低速风洞上,对某型高负荷涡轮静叶栅进行了吹风试验.应用五孔球头测针,详细测量了在三个冲角下由栅前至栅后7个横截面内气流参数沿叶高和节距的分布.试验结果表明,沿叶高变负荷结合叶片弯曲,在满足高负荷要求的条件下能够控制边界层的集聚、转捩与分离.在主流区采用前加载叶型,保证叶片能承担高负荷.在两个端壁区采用后部加载叶型,并通过叶片正弯进一步降低气动负荷,从而减小端壁横向压力梯度,削弱端壁横向二次流.正、负冲角仅影响叶片前缘吸力面或压力面的静压分布,引起气动负荷的增加与减小.研究的高负荷涡轮叶栅具有良好的冲角适应性.
In a low-speed ring cascade wind tunnel,aerodynamic tests were fulfilled on a large enthalpy drop static cascade in the middle stage of a steam turbine.From the front to the back gate,the flow parameters in seven cross sections along the blade height and pitch at three incidences were measured in detail with the application of five-hole pin ball test.The results show that,in order to meet the requirements of high loading conditions,the combination of highly variable loading and blade bending along span-wise can control the accumulation,transition and separation of boundary layer.Fore-loaded blade profiles were applied in the main passage area to ensure that the blade could withstand high loading.After-loaded blade profile was applied to the end wall and the positive bending blade further reduced aerodynamic loading,the end wall lateral pressure gradient was cut down to weaken the end wall lateral secondary flow.Positive and negative incidences affect only the static pressure distribution at the leading edge of the suction side or pressure side,causing the increase and decrease of aerodynamic loading.The turbine cascade with high aerodynamic loading has a good adaptability of incidence.
出处
《航空动力学报》
EI
CAS
CSCD
北大核心
2011年第12期2722-2730,共9页
Journal of Aerospace Power
关键词
涡轮叶栅
高负荷
弯叶片
二次流
气动性能
turbine cascade
high loading
curved blade
secondary flow
aerodynamic performance
