A Novel Dynamic Measurement Method for Rotor-Stator Axial Clearance

Accurate measurement of the axial clearance between the rotor and stator in an aeroengine is crucial for precise engine design and aerodynamic analysis. It also provides a significant reference for correcting measurements obtained through other noncontact methods. This article proposes a triangulation method based on time of arrival (TMBT) for measuring axial clearance, which can simultaneously measure rotor speed and has the potential to replace traditional once-per-revolution (OPR) sensors. The mechanism of measurement error is analyzed, and methods for error estimation and correction are proposed. A simulated rotor test bench was set up in the laboratory to achieve dynamic calibration and performance testing of the sensor and to verify the effectiveness of the error estimation and correction methods. Experimental results show that the measurement accuracy of this method is better than 0.05 mm (for a range of 2.5-8.0 mm) and better than 1.5% (for a range of 2.5-11.0 mm). The proposed error estimation and correction methods effectively estimate and correct measurement errors caused by sensor installation positional offsets.