High-temperature resistant resonant cavity microwave sensor for precision blade tip clearance monitoring in aeroengines.

In the aerospace field, accurate measurement of the blade tip clearance of aeroengines is highly important for enhancing engine performance and ensuring flight safety. Existing measurement techniques, such as capacitive, inductive, and optical methods, have limitations in terms of stability, application range, or tolerance to complex environments. Moreover, the problem of sensor performance degradation in high-temperature environments has not been effectively resolved. This study aims to design a high-temperature resistant microwave blade tip clearance sensor to overcome these limitations. The sensor structure is designed on the basis of the resonant cavity principle and electromagnetic field theory. The sensor has a radiation efficiency of 97% near 24 GHz, a reflection coefficient as low as 0.01, good measurement resolution within the 0-6 mm clearance measurement range, and the impact of changes in the dielectric constant at high temperatures on its performance is controllable. This research provides a new solution for the measurement of aeroengine blade tip clearance, improving the stability and reliability of the measurement.