高压涡轮叶尖径向运行间隙概率设计

为了改善高压涡轮叶尖径向运行间隙(BTRRC,Blade-Tip Radial Running Clearance)设计和控制合理性,考虑典型载荷下的热载荷和机械载荷和合理选取随机变量,在确定性分析基础上对BTRRC进行了概率设计.通过确定性分析,得出涡轮盘、叶片和机匣的径向变形以及BTRRC随时间变化规律,并找出危险点(t=180 s)作为概率设计的计算点.通过概率分析,不但得到了各部件径向变形的概率分布特征及不同稳态叶尖间隙δ下的失效数、失效概率和可靠度,还找到了影响它们径向变形和BTRRC的主要因素.综合考虑航空发动机可靠性和效率,将δ设定为1.95 mm为宜,满足设计和工程要求,为BTRRC的控制和设计提供了依据.

Probabilistic design for blade-tip radial running clearance of HPT

To improve the blade-tip radial running clearance(BTRRC) design of aeroengine high pressure turbine(HPT), the probabilistic analysis of BTRRC was implemented based on deterministic analysis through considering the heat and mechanical loads of objects (disk, blade and casing) and selecting random variables legitimately. The variation of BTRRC and the radial deformations of objects with time were gained and the minimum clearance at t=180 s was regarded as the probabilistic analysis point through the deterministic analysis. In addition, the probabilistic distribution features and failure numbers, failure probabilities and reliabilities under different static clearance δ predetermined were obtained besides the major factors impacting on the deformations and BTRRC through the probabilistic analyses. The results show that δ=1.95 mm is advisable to select as an effective reference for the control and design of BTRRC for satisfying the aeroengine design and engineering.