Ceramic-Integrated Eddy Current Sensor for Blade Tip Clearance Measurement: Design and Performance Evaluation

Blade tip clearance (BTC) is a critical parameter for the thrust, fuel consumption, and operational safety of aero-engines, and its accurate monitorinfg is of significant engineering importance. Traditional eddy current sensors (ECS) in BTC measurement often employ wound coil structures, which suffer from issues such as poor consistency and limited geometric shapes, restricting further optimization of electromagnetic performance. This paper proposes a novel ECS based on ceramic-integrated printed coils. The ECS uses screen printing technology to directly print metal coils onto ceramic substrates and integrate them into a single unit, allowing the coils to be designed with high precision into any topology structure, with high consistency, structural stability, and high temperature tolerance. Performance studies indicate that the sensor can be manufactured with an accuracy of 0.2 mm or better, and the sensor with a line width and spacing of 0.2 mm performed the best in the test. Not only does it exhibit the best electromagnetic performance at room temperature, but it also shows an electromagnetic performance variation of less than 1% after a 24 h aging test at 800 °C. Additionally, it provides stable peak-to-peak and periodic responses to changes in BTC within the range of 0 to 600 rpm for the fan motor. This study provides a promising method for accurate and stable BTC measurement at high temperatures.