A Sensor for Real-Time Online Monitoring of the Rotor Axial Displacement of Aeroengine Based on Microwave Coaxial Resonator

In this article, a sensor for real-time online monitoring of the rotor axial displacement of an aeroengine based on a microwave coaxial resonator (MCR) is proposed. During the monitoring process, different axial displacements of the engine rotor will make MCR introduce different additional grounding capacitance, resulting in MCR generating different resonance statuses. Therefore, the monitoring and warning of the axial displacement of the engine rotor can be achieved by reading the resonance characteristics of the MCR in real time. Furthermore, the proposed sensor is also endowed with low-flow resistance characteristics since introducing the design of the diversion hole. Finally, the simulation and measurement results of the proposed sensor have the rotor axial displacement measuring and monitoring accuracy of
$25\mu $
m within
$2000\mu \text{m}$
, an average accuracy of
$150\mu $
m within 2000–
$5000\mu \text{m}$
, and a full monitoring range response bandwidth of 6.65 GHz (1.33 MHz/
$\mu \text{m}$
). It can be predicted that the proposed sensor will be of greater value in the field of designing, testing, and health management of aeroengine.