涡轮叶尖间隙检测与数值分析研究

发布时间：2018-03-01 19:08

本文关键词： 叶尖径向间隙有限元模型涡流密度数值仿真温度和离心载荷　出处：《南京航空航天大学》2016年硕士论文　论文类型：学位论文

【摘要】：航空发动机的涡轮叶尖径向间隙对发动机工作效率和安全具有重要影响,本文围绕涡轮叶尖径向间隙数值分析与检测技术中的若干问题开展研究。本文首先开展了涡轮叶尖间隙数值仿真研究,以某型航空发动机低压涡轮为研究对象,综合考虑离心载荷和温度载荷的影响,结合表征该型发动机整机性能的起动数学模型,提出了在发动机起动的全过程涡轮叶尖径向间隙有限元仿真方法。仿真结果表明在发动机起动过程中,机匣和叶片的径向变形主要受温度载荷的影响,轮盘的径向变形主要受离心载荷影响。综合对比数值分析计算结果和该型发动机手册数据,显示两者基本相等,验证了数值分析结果的正确性。本文分析了电涡流传感器的基本原理,根据电涡流原理和有限元建模理论,建立了电涡流三维有限元模型,获得了被测导体中电涡流分布情况;对比具有不同探头形状的传感器的电涡流分布,设计了用于叶尖间隙测量的传感器探头线圈;根据涡轮叶尖径向间隙特性和现有传感器测量电路,设计了新的测量电路原理图。利用所设计测量电路和传感器探头制作电涡流传感器,并对其静态特性和动态特性开展实验研究。对静态标定数据进行最小二乘直线拟合,结果表明设计制作的传感器在2~11mm的测量区间线性度较好,对静态标定数据进行曲线拟合,显示高斯法拟合曲线与标定数据吻合度最高。动态测量实验中,设计了轮齿高低变化的音轮用来模拟叶尖间隙变化,对传感器通过单组轮齿进行周向标定,并在不同转速下测量叶尖间隙,将所测数据与标定数据对比,显示所设计制作传感器能够应用于测量叶尖径向间隙。
[Abstract]:The radial clearance of the turbine tip of an aeroengine has an important effect on the efficiency and safety of the engine. In this paper, some problems in the numerical analysis and detection of radial clearance of turbine tip are studied. Firstly, numerical simulation of tip clearance of turbine blade is carried out, and a low pressure turbine of an aero-engine is taken as an object of study. Considering the influence of centrifugal load and temperature load, combined with the starting mathematical model to characterize the performance of the engine, A finite element simulation method for the radial clearance of turbine blade tip in the whole process of engine starting is presented. The simulation results show that the radial deformation of casing and blade is mainly affected by temperature load during engine starting. The radial deformation of the wheel disk is mainly affected by centrifugal load. Compared with the numerical analysis results and the data of the engine manual, it is shown that the two are basically equal. In this paper, the basic principle of eddy current sensor is analyzed. According to the theory of eddy current and finite element modeling theory, the three-dimensional finite element model of eddy current is established, and the eddy current distribution in measured conductor is obtained. Comparing the eddy current distribution of sensors with different probe shapes, the transducer coil for measuring tip clearance is designed, and according to the radial clearance characteristics of turbine blade tip and the current sensor measuring circuit, A new measuring circuit schematic diagram is designed. The eddy current sensor is fabricated by using the designed measuring circuit and sensor probe. The static and dynamic characteristics of the eddy current sensor are studied experimentally. The static calibration data are fitted by the least square straight line. The results show that the linearity of the sensor designed and manufactured is good at the measuring range of 210mm. The curve fitting of static calibration data shows that the fitting curve of Gao Si method is the best with the calibration data. A sound wheel with varying gear teeth was designed to simulate the change of tip clearance. The sensor was calibrated circumferentially through a single set of gear teeth. The tip clearance was measured at different rotational speeds, and the measured data were compared with the calibrated data. It shows that the sensor can be used to measure radial clearance of blade tip.
【学位授予单位】：南京航空航天大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：V232

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