摘要
在涡轮转静叶片排之间喷入冷气可以阻止高温燃气进入盘腔,但是冷气与主流的掺混损失对涡轮气动性能不利。本文采用数值计算的方法,研究了转静叶片排之间封严腔轴向位置和轴向间隙的变化对涡轮性能和端区流动的影响。结果表明,封严出流与主流的剪切作用形成了诱导涡,诱导涡随后发展成为通道涡并占据了端区二次流的主导地位。封严腔轴向位置和轴向间隙的改变使等熵效率和封严效率产生了相反的变化,因此在设计时要兼顾气动性能和冷却要求进行综合考虑。
Cooling flow is injected into the mainstream through the inter-stage gap in turbines to avoid hot gas ingestion.However,losses due to the mixing process between main flow and cooling flow directly lead to the penalty of turbine performance.In order to investigate the effects of rim seal cavity axial position and axial clearance on turbine performance and end wall flows,3-D steady numerical simulation of was conducted.The results indicate that shear induce vortex is formed due to the shear interaction between main flow and cooling flow and develops into hub passage vortex which dominates the hub end wall region.Variation of rim seal cavity axial position and axial clearance result in the opposite trend of isentropic efficiency and sealing efficiency.Thus,turbine aerodynamic performance and cooling requirements should be made a compromise in the design process.
出处
《工程热物理学报》
EI
CAS
CSCD
北大核心
2015年第3期492-495,共4页
Journal of Engineering Thermophysics
基金
中国民航大学科研启动基金项目(No.2014QD06X)
关键词
封严腔
轴向位置
轴向间隙
通道涡
涡轮性能
rim seal cavity
axial position
axial clearance
passage vortex
turbine performance
