叶尖粗糙度与倾角对光纤传感器输出特性影响

航空发动机涡轮叶片叶尖间隙变化影响发动机效率也蕴含丰富的发动机健康状态信息。实际叶尖间隙变化表现为3维变化,且叶尖表面受高温气流剥蚀等影响表面粗糙度发生变化。为探究其对光纤传感器测量叶尖间隙精度的影响,利用ZEMAX光学仿真软件分析了双圈同轴式光纤传感器在叶尖表面粗糙度变化和倾角变化影响下的输出特性,并搭建3维叶尖间隙静态标定平台对上述影响进行试验。结果表明:粗糙度和倾角增大均导致传感器灵敏度降低、零点位置后移。该结果为实现叶尖间隙变化的3维精确测量提供理论和试验依据。

Influence of Roughness and Inclination of Blade Tip on Output Behavior of Reflective Fiber Bundle Sensor

The clearance change between blade tip and turbine shroud both influences the efficiency and reflects the health information of the aeroengine. In reality, the clearance change was a three-dimensional variation and the roughness of the blade tip surface was influenced by the denudation of the high-temperature gas flow. The influence of roughness and inclination of turbine blade tip surface to the output behavior of two-circle reflective coaxial fiber bundle sensor were analyzed by using the optical simulation software ZEMAX. A static calibration platform of three-dimensional tip clearance change was built to verify the simulation results. Results show that both the increase of the roughness and the inclination of turbine blade tip surface cause the sensor sensitivity to decrease and the zero position to move backward, which provides the theoretical and experimental basis for the accurate measurement of three-dimensional tip clearance change.