基于薄膜传感阵列测量的压气机转子叶尖涡流特性研究

In recent years, the phenomenon of inner aerodynamic becomes unstable, noise level increase dramatically and the blade of compressor vibrating non-synchronously with the rotary speed and blade passing frequency which leads to the blade fatigue crack.   It is considered that it is caused by the vortex propagation and feedback between the blade lattices. Hence, study on this has become hot topic in aero engine research field. However, due to the constriction of present measurement technique, the pressure field and vortex over the blade tip still can’t be measured and captured. It makes this study difficult. Aiming at this problem, an EMFI film sensor based vortex pressure field measure method of blade tip clearance is proposed to be studied in this project. The study will start with the investigation on the piezoelectric characteristics of the EMFI material and its affect factors, the sensor array with high frequency and space resolution will be designed and produced after investigation. The tracing and capture measurement method and principle of the rotating vortex pressures field will be study deeply, the algorithm for this method will be bring forth. The calibration and installation technique are also will be investigated to make the measurement accurate. Finally, the EMFI film sensor based measurement system will be built up to study the vortex field and its propagation. It is expected that the result will deliver solid support to the aerodynamics-structure-accoustics coupling study of compressor blade.

近年来国内外航空发动机压气机时常出现内部非定常气动恶化，噪声加剧，转子叶片非同频谐振并导致叶片断裂的现象，普遍观点认为是叶尖涡流层在同级叶排空腔中传播与反馈所致 ，其已成为国内外研究热点。由于测试手段的局限，当前对实际压气机尚不能有效捕捉叶尖涡 流分布及演变特性，使研究遭遇瓶颈。针对此问题，本项目拟研究一种压气机叶尖涡流层脉动压力场测试方法，研究薄膜压电材料的压电特性和影响因素，提出基于电薄膜材料的宽频响、高空间分辨率的薄膜传感阵列的设计与制备方法；重点研究叶尖高速旋转压力场捕捉跟踪测量方法和基本原理，提出涡流传播与反馈的显示与跟踪分析算法；建立薄膜传感器阵列标定系统，解决压力场的准确测量问题；研究传感器阵列的贴装工艺，提出稳定可靠的安装连接方法；最终建立完整的压气机叶尖场压场测量系统，测量研究叶尖涡流形成机制和传播特性，为压气机叶片气-固-声耦合研究提供支撑。

压气机转子叶尖涡流特性是反映气动、叶片以及声场耦合的关键，受限于现有的测试手段，仅能进行有限测点的测量，还无法捕捉叶尖的涡流分布以及随时间的传播演变特性，因此，本课题重点研究了基于薄膜传感器阵列的压气机转子叶尖涡流特性。研究了压气机数值仿真模型，分析了叶尖涡流在不同工况下的产生、演化和传播特性；研究了高空间分辨率、高频响的薄膜传感器阵列的制备、封装、信号引出和安装工艺；研究了薄膜传感器各层材料力学参数和厚度参数对薄膜传感器性能的影响规律，依据分析结果对薄膜传感器进行了优化；针对压气机一级转子叶片上方机匣结构，设计、加工了薄膜传感器阵列；研究了基于声激励和激波管的动态特性标定方法和标定装置；研究了基于薄膜传感器阵列的叶尖脉动压力场测试技术并搭建了测试系统。.取得的主要研究成果为：给出了薄膜传感器阵列的制备、封装、信号引出和安装工艺，优化了薄膜传感器各层力学和结构参数，提出了薄膜传感器基于声激励和激波管的动态特性标定方法并搭建了相应的标定装置，给出了基于薄膜传感器阵列的叶尖脉动压力场测试方法，基于薄膜传感器阵列的测试结果应用时空插值算法获得了叶尖涡流在不同工况下的产生和变化特性。本项目提出的压气机叶尖压力场测量方法与传感测量装置可以用于压气机转子叶尖、静子叶片表面乃至转子叶片表面的脉动压力测量，能够为深入研究压气机叶片气-声-固耦合研究，提供有效的测试分析手段和数据支撑。