A review of blade tip clearance–measuring technologies for gas turbine engines

Yu, Bing; Ke, Hongwei; Shen, Enyu; Zhang, Tianhong

doi:10.1177/0020294019877514

Cited by 23 publications

(11 citation statements)

References 72 publications

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“…erefore, the equivalent impedance Z becomes a single-valued function of the tip clearance x [21]. rough the eddy current sensor conversion circuit, the change in the equivalent impedance Z is finally converted into a change in the output voltage U.…”

Section: Measurement Principle Of Eddy Currentmentioning

confidence: 99%

An Improved Blade Vibration Parameter Identification Method considering Tip Clearance Variation

Zhang

Wang

2021

Shock and Vibration

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Blade tip timing (BTT) technology is the most effective means for real-time monitoring of blade vibration. Accurately extracting the time of blade tip reaching the sensors is the key to ensure the accuracy of the BTT system. The tip clearance changes due to various complex forces during high-speed rotation. The traditional BTT signal extraction method does not consider the influence of tip clearance change on timing accuracy and introduces large timing errors. To solve this problem, a quadratic curve fitting timing method was proposed. In addition, based on the measurement principle of the eddy current sensors, the relationship among the output voltage of the eddy current sensor, tip clearance, and the blade cutting magnetic line angle was calibrated. A multisensor vibration parameter identification algorithm based on arbitrary angular distribution was introduced. Finally, the experiments were conducted to prove the effectiveness of the proposed method. The results show that in the range of 0.4 to 1.05 mm tip clearance change, the maximum absolute error of the timing values calculated by the proposed method is 26.0359 us, which is much lower than the calculated error of 203.7459 us when using the traditional timing method. When the tip clearance changed, the constant speed synchronous vibration parameters of No. 0 blade were identified. The average value of the vibration amplitude is 1.0881 mm. Compared with the identification results without changing tip clearance, the average value error of the vibration amplitude is 0.0017 mm. It is proved that within the blade tip clearance variation of 0.4 to 0.9 mm, the timing values obtained by the proposed timing method can accurately identify the vibration parameters of the blade.

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Section: Measurement Principle Of Eddy Currentmentioning

confidence: 99%

An Improved Blade Vibration Parameter Identification Method considering Tip Clearance Variation

Zhang

Wang

2021

Shock and Vibration

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“…The assembly gap is usually applied to indicate the assembly quality in some assembly task such as the car body assembly, 1 tip clearance in turbine, 2 clearance of Gyro motor, 3 etc. These gaps are measured for adjustment or record by manual gauge 4 in past.…”

Section: Introductionmentioning

confidence: 99%

An edge identification method for gap in-line measurement based on fillet assumption

Zhao

Sun

Cao

et al. 2022

Measurement and Control

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The optical measurement technology could reduce manual work and improve quality in assembly. The confocal scanning scheme is proposed to measure the narrow gap in-line but it is hard to identify the edges of a gap. This paper proposed an edge definition and presented an edge identification method for gap measurement. The edge profile is defined as a part of a circle, which could be identified by the shutter time feature. The defined edge point could be calculated by fitting the edge profile, and then the width of a gap section is calculated by two edge points. The width of a gap can be evaluated by the average of several gap section. The experimental results indicate that the repeatability of the method is less than 2 µm and the precision of the measurement is higher than ±2.5 µm. The proposed method is feasible for in-line measurement application in assembly.

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“…BTT and tip clearance (TC) sensors have a lot in common, and some types offer both measurements [10]. However, sensors can be optimized either for clearance or vibration measurement.…”

Section: Introductionmentioning

confidence: 99%

High Temperature Magnetic Sensors for the Hot Section of Aeroengines

et al. 2021

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Magnetic sensors are widely used in aeroengines and their health management systems, but they are rarely installed in the engine hot section due to the loss of magnetic properties by permanent magnets with increasing temperature. The paper presents and verifies models and design solutions aimed at improving the performance of an inductive sensor for measuring the motion of blades operated at elevated temperatures (200–1000 °C) in high pressure compressors and turbines. The interaction of blades with the sensor was studied. A prototype of the sensor was made, and its tests were carried out on the RK-4 rotor rig for the speed of 7000 rpm, in which the temperature of the sensor head was gradually increased to 1100 °C. The sensor signal level was compared to that of an identical sensor operating at room temperature. The heated sensor works continuously producing the output signal whose level does not change significantly. Moreover, a set of six probes passed an initial engine test in an SO-3 turbojet. It was confirmed that the proposed design of the inductive sensor is suitable for blade health monitoring (BHM) of the last stages of compressors and gas turbines operating below 1000 °C, even without a dedicated cooling system. In real-engine applications, sensor performance will depend on how the sensor is installed and the available heat dissipation capability. The presented technology extends the operating temperature of permanent magnets and is not specific for blade vibration but can be adapted to other magnetic measurements in the hot section of the aircraft engine.

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A review of blade tip clearance–measuring technologies for gas turbine engines

Cited by 23 publications

References 72 publications

An Improved Blade Vibration Parameter Identification Method considering Tip Clearance Variation

An Improved Blade Vibration Parameter Identification Method considering Tip Clearance Variation

An edge identification method for gap in-line measurement based on fillet assumption

High Temperature Magnetic Sensors for the Hot Section of Aeroengines

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