人为失谐改善叶盘气弹稳定性的机理分析  

Mechanism analysis for aero-elastic stability improvement of intentional mistuned bladed disk

作　　者：范雨[1,2] 刘鑫 李琳[1,2] 余晓平 FAN Yu;LIU Xin;LI Lin;YU Xiaoping(School of Energy and Power Engineering,Beihang University,Beijing 100191,China;Beijing Key Laboratory of Aero-Engine Structure and Strength,Beihang University,Beijing 100191,China;Aviation College,Inner Mongolia University of Technology,Huhehaote 010051,China;China Academy of Aerospace Aerodynamics,China Aerospace Science and Technology Corporation,Beijing 100074,China)

机构地区：[1]北京航空航天大学能源与动力工程学院,北京100191 [2]北京航空航天大学航空发动机结构强度北京市重点实验室,北京100191 [3]内蒙古工业大学航空学院,呼和浩特010051 [4]中国航天科技集团公司中国航天空气动力技术研究院,北京100074

出　　处：《航空动力学报》2022年第10期2142-2156,共15页Journal of Aerospace Power

基　　金：国家科技重大专项(J2019-Ⅳ-0023-0091,J2019-Ⅳ-0005-0073);航空科学基金(2019ZB051002);先进航空动力创新工作站(HKCX2020-02-013,HKCX2020-02-016,HKCX2022-01-009)。

摘　　要：理解人为失谐提升叶盘气动弹性稳定性的机理,有助于提高航空发动机叶盘的结构设计水平。首先,通过将失谐叶盘的气弹耦合模态投影到谐调模态张成的线性空间中,获得了以谐调叶盘气动阻尼比线性叠加表示的失谐叶盘气动阻尼比的解析表达式。从理论上证明了:失谐气弹耦合模态振型中包含多个彼此独立的谐调叶盘模态振型的贡献;气动阻尼比水平较高的谐调叶盘模态的参与提高了失谐叶盘的气弹稳定性。接着,提出了失谐叶盘气弹稳定性的预测方法,在计算过程中先分别分析失谐和气弹耦合的模态特性,再相互结合预测失谐叶盘的气动阻尼比水平。该方法只需进行一次气弹耦合分析,一是在实际设计中可降低对失谐设计叶盘气弹稳定性实验测量需求,二是降低仿真过程中的计算量,加快失谐模式寻优过程。最后,采用具有NASA-Rotor37叶型的叶盘作为研究对象,在多种失谐模式和失谐强度下验证了上述理论的正确性。结果表明:解析表达式误差小于0.1%;预测方法对稳定边界有一定的高估且误差在5%以内,对于总体影响规律的预测与精确解一致。By projecting the aero-elastic modes of the mistuned bladed disk to the modal space spanned by the tuned modes,a closed-form expression of the mistuned aerodynamic damping ratio as a linear superposition of the tuned damping was obtained.It was theoretically demonstrated that:a mistuned aero-elastic mode was constructed by several tuned and independent modes;and the contribution of the tuned modes with high aeroelastic damping can increase the aeroelastic damping of the mistuned mode.A method to predict the aerodynamic damping ratio of the mistuned bladed disk was proposed.It started with respective analysis of aero-elastic coupling and mistuning,and the aerodynamic damping ratio of the mistuned modes can be predicted.A single-time aeroelastic analysis was required for two significant benefits.One is reducing the experimental measurements and the other is decreasing the calculation cost to accelerate the optimization process of mistuning pattern.The bladed disk with NASA-Rotor37 blade profile was considered,and several typical mistuning patterns were applied with different levels of mistuning strength.Results showed that the closed-form expression had an error lower than 0.1%.The prediction method would overrate the stability boundary with error lower than 5%,so it is capable to capture the overall trends of the accurate results.

关 键 词：叶盘 人为失谐 气弹稳定性 模态投影 定量分析 

分 类 号：V232.4[航空宇航科学与技术—航空宇航推进理论与工程]