分流通道对台阶型篦齿封严性能影响研究  

Investigation on Effects of Diversion Channels on Leakage of Stepped Labyrinth Seal

作　　者：董红伟 谭晓茗[1] 张庆才 张靖周[1] DONG Hongwei;TAN Xiaoming;ZHANG Qingcai;ZHANG Jingzhou(College of Energy and Power Engineering,Nanjing University of Aeronautics&Astronautics,Nanjing 210016,China)

机构地区：[1]南京航空航天大学能源与动力学院,南京210016

出　　处：《南京航空航天大学学报》2024年第4期622-629,共8页Journal of Nanjing University of Aeronautics & Astronautics

基　　金：航空发动机及燃气轮机基础科学中心项目(P2022‑A‑Ⅲ‑003‑001)。

摘　　要：为提高涡轮级间篦齿的封严性能,设计了一种带分流通道的台阶型篦齿封严结构,研究了不同压比与转速下分流通道对篦齿封严泄漏特性和传热特性的影响规律,并与光滑篦齿进行对比。结果表明:在衬套上增设一个分流通道后,处于通道出口处的气流在离心力作用下被卷吸进通道,增强了篦齿的封严效果;分流通道的周向间隙率β越大,封严效果越佳,当周向间隙率β为3时,绝热壁面流量系数为13.47%,绝热壁面风阻温升为48.7 K;分流通道数量增加,篦齿的泄漏加剧;随着压比增加,密封泄漏量增大,分流通道可以引导核心射流回流,故泄漏量增速逐渐变缓而绝热壁面风阻温升增速加剧;当转速从3×10^(3)r/min增加到2.1×10^(4)r/min,气流摩擦耗散加剧,篦齿绝热壁面流量系数逐渐降低,绝热壁面风阻温升逐渐升高,分流通道对高转速下篦齿的封严效果提升显著。To improve the leakage performance of the turbine interstage seal,a stepped labyrinth seal structure with a diversion channel is designed.The influence of the diversion channel on the leakage and heating characteristics of the labyrinth seal is investigated under various pressure ratios and rotational speeds,and compared with the smooth labyrinth seal.The results show that adding a diversion channel on the casing enhances the sealing effect of the labyrinth seal by allowing airflow at the outlet to be rolled and sucked into the channel under the effect of centrifugal force.The larger the circumferential clearance rateβof the diverter channel,the better the sealing performance.When the circumferential clearing rateβis 3,the insulated wall flow coefficient is 13.47%and the insulated wall wind resistance temperature rises by 48.7 K.The increase in the number of diversion channels intensifies the leakage of the seal.As the pressure ratio grows,the sealing leakage increases,and the diversion channel may guide the core flow return,so the leakage growth rate gradually slows down while the insulated wall wind resistance temperature rise growth rate increases.As the rotational speed increases from 3×10^(3) r/min to 2.1×10^(4) r/min,the airflow friction diffusion worsens,the labyrinth seal insulated wall flow coefficient decreases,the insulated wall wind resistance temperature rises,and the diversion channel improves the labyrinth seal’s sealing effect at high rotational speed.

关 键 词：数值模拟 分流通道 台阶型篦齿封严 流量系数 风阻温升 

分 类 号：V233.93[航空宇航科学与技术—航空宇航推进理论与工程]