带缘板修型的静盘深腔型复合封严试验  

Experiment on composite rim seal with deep cavity in static disc and modified platform

作　　者：张庆才 刘松 王钦钦[2] 谭晓茗 张靖周[1] 郭文[2] Qingcai ZHANG;Song LIU;Qinqin WANG;Xiaoming TAN;Jingzhou ZHANG;Wen GUO(College of Energy and Power Engineering,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,China;AECC Sichuan Gas Turbine Establishment,Chengdu 610500,China;Research Institute of Aero-Engine,Beihang University,Beijing 102206,China)

机构地区：[1]南京航空航天大学能源与动力学院,南京210016 [2]中国航发四川燃气涡轮研究院,成都610500 [3]北京航空航天大学航空发动机研究院,北京102206

出　　处：《航空学报》2023年第5期40-53,共14页Acta Aeronautica et Astronautica Sinica

基　　金：国家科技重大专项(2017-Ⅲ-0001-0025)。

摘　　要：采用CO_(2)气体体积分数测量法研究一种带缘板修型的静盘深腔型复合封严结构。同时选取轴向封严结构和叠覆封严结构作为比较基准,重点关注主流雷诺数(0.75×10^(5)~9.4×10^(5))、封严流量(流量比0.2%~2.5%)、旋转雷诺数(1.6×10^(5)~8.1×10^(5))等典型工况参数对盘腔内压力分布和封严效率的影响情况;并在此基础上开展了相应的数值研究,获得了封严腔室内详细的流场信息。结果表明:在试验设计工况范围内,主流雷诺数的改变对静叶尾缘和动叶前缘的周向压力分布影响显著。主流雷诺数增加,主流通道内压力升高,主流气体入侵加剧;增加封严流量有利于提高盘腔内压力,从而提升盘腔封严效率,但这对静叶尾缘压力影响较小;增加旋转雷诺数会增大静叶尾缘和动叶叶间通道前缘的静压,加重主流气体入侵,降低盘腔封严效率。相比轴向封严结构,叠覆封严结构由于高半径封严容腔的设置,改变了盘腔流场结构,有效地将主流气体阻隔在封严容腔内,保证了低半径盘腔的封严效率在80%以上。新型封严结构的静盘深腔和缘板造型设置,不仅保证了低半径盘腔的封严效率在85%以上,还能提高高半径处封严容腔的封严效率,在低流量比(0.2%)工况下,其封严容腔区域的封严效率提升了10%。In this study,the composite rim seal with the deep cavity in the static disc and the modified platform was investigated by measuring the CO_(2)concentration.An axial and an overlapping rim seal were used as the baseline to compare and analyze the effects of the mainstream Reynolds number(0.75×10^(5)-9.4×10^(5)),the sealing flow rate(flow rate ratio 0.2%-2.5%),and rotating Reynolds number(1.6×10^(5)-8.1×10^(5))on the distribution of pressure and the sealing efficiency in the disc cavity.A corresponding numerical study was also carried out to obtain detailed flow characteristics.The results show that the main flow Reynolds number significantly affected the circumferential pressure distribution in the main flow channel.With the increase of the main flow Reynolds number,the pressure in the main flow channel also increased and the gas ingestion intensified.The higher coolant flow rate was beneficial to improvement of the sealing efficiency of the disc cavity by increasing the pressure in the disc cavity,but had less effect on the pressure at the trailing edge of the vane.An improvement in the rotating Reynolds number increased the static pressure in the main flow channel and decreased the sealing efficiency of the disc cavity.Compared with the axial rim seal,the flow structure of the overlapping rim seal cavity was changed by the setting of the high-radius sealing cavity,which effectively blocks the mainstream gas inside the sealing cavity and ensures that the sealing efficiency of the low-radius cavity is above 80%.The composite rim seal structure not only guarantees the sealing efficiency of 85%at the low-radius disc cavity,but also improves the sealing efficiency at the high-radius sealing cavity.At a low sealing flow ratio(0.2%),the sealing efficiency of the composite rim seal structure is 10%higher than the other two rim seal structures.

关 键 词：复合封严 封严效率 主流雷诺数 旋转雷诺数 燃气入侵 

分 类 号：V231.3[航空宇航科学与技术—航空宇航推进理论与工程]