航空发动机叶尖径向间隙静电监测方法

提出航空发动机叶尖径向间隙静电监测方法,分别对叶尖荷电在点电荷与电荷分布条件下的静电感应过程建立数学模型,得到感应电荷量与叶尖径向间隙值、叶尖周向位置及叶尖电荷分布的关系。设计并搭建叶尖径向间隙静电监测模拟实验台,提取时域特征参数并分析叶尖径向间隙值及叶尖局部曲率对静电水平的影响。数学模型计算结果表明:①感应电荷量与叶尖径向间隙及叶尖相对传感器的径向位置绝对值呈负相关;②感应电荷量与叶尖所带电荷量呈正相关,且与电荷密度分布有关;③感应电荷量与叶尖尺寸及传感器尺寸有关。实验结果表明静电信号方均根值和整流平均值与叶间径向间隙值呈负相关,与叶尖局部曲率呈正相关,其结果与理论模型相符。 

Electrostatic monitoring method for blade tip radial clearance of aero-engine

An electrostatic monitoring method for blade tip radial clearance of aero-engine was proposed. The electrostatic induction mathematical models of the blade tip charged in the form of point charge and distributed charge were established respectively, by which the relationship between the induced charge and the radial clearance, circumferential position and charge distribution of the blade tip was obtained. An electrostatic monitoring simulation experiment platform was designed and built. Several time domain characteristic parameters were extracted so that the influences of blade tip radial clearance and local curvature on electrostatic level were analyzed. The mathematical models showed that: (1) the amount of induced charge was negatively related to the blade tip radial clearance and the absolute value of the blade tip radial position relative to the sensor; (2) the amount of induced charge was positively related to the amount of charge on the blade tip, and also was influenced by the distribution of charge density; (3) the amount of induced charge was related to the size of both blade tip and the sensor. The experimental results showed that the root mean square value and average rectified value of electrostatic signal were negatively related to the blade tip radial clearance, but were positively related to the local curvature of blade tip, which were consistent with the results of theoretical models.