叶片排间耦合对跨声速压气机转子颤振特性影响研究

Effects of Inter-Row Coupling on Flutter Characteristics of a Transonic Compressor Blade Row

关键词:  压气机  排间耦合  颤振特性  谐波平衡  压力波反射

Key words:  Compressor  Inter-row coupling  Flutter characteristics  Harmonic balance method  Pressure wave reflection

摘要:

高推重比、强紧凑性的设计要求迫使压气机相邻叶片排之间的距离进一步减小，在加剧排间非定常扰动的同时，势必对叶片的气动弹性稳定性产生影响。本文针对1.5级跨声速压气机，基于谐波平衡非定常求解技术，结合单向耦合的能量法，开展排间耦合对1.5级跨声速压气机叶片颤振特性影响研究。通过对比分析非定常/定常混合模型的颤振预测结果可以发现：排间压力波反射对振荡叶排压力脉动特性的影响是造成转子颤振特性差异的主要原因。上、下游静叶对转子气动弹性稳定性恶化程度并不相同，且不符合线性叠加原理。对于近失速工况，非定常压力波反射导致转子叶片气动阻尼系数减小75%，定常/非定常混合预测方法可能导致颤振特性预估过于乐观。

Abstract:

The design requirements of high thrust weight ratio and strong compactness force the distance between adjacent blade rows of the compressor to be further reduced， which will not only aggravate the unsteady disturbance between rows， but also affect the aeroelastic stability of the blades. For this reason， the effects of inter-row coupling on flutter characteristics of a 1.5-stage transonic compressor blade were studied based on harmonic balance unsteady solution technology and energy method in one-way coupling manner. By comparing and analyzing the flutter prediction results of the unsteady/steady hybrid model， it can be found that the effects of inter-row pressure wave reflection on the transient pressure response of oscillating blade row are the main reason for the difference of rotor flutter characteristics. And the deterioration degree of upstream and downstream stator vanes to aeroelastic stability of the rotor blades is different and does not conform to the linear superposition principle. For the near stall condition， the unsteady pressure wave reflection reduces the aerodynamic damping coefficient of rotor blades by 75%. The unsteady/steady hybrid prediction method may lead to over optimistic prediction of flutter characteristics.