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Abstract
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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Lallana PC, Aldabaldetreku G, López A, Montero DS, Durana G, Mateo J, Losada MÁ, Zubia J, Vázquez C. Sensing Applications in Aircrafts Using Polymer Optical Fibres. SENSORS 2021; 21:s21113605. [PMID: 34064285 PMCID: PMC8196816 DOI: 10.3390/s21113605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 05/13/2021] [Accepted: 05/17/2021] [Indexed: 11/16/2022]
Abstract
We report on recent advances in the use of inexpensive polymer optical fibres (POFs) for sensing applications in avionics. The sensors analysed in this manuscript take advantage of the unique properties of polymers, such as high flexibility, elasticity, and sensitivity, and they range from strain, elongation, and vibration interrogators to level and temperature meters, leading to cost-effective techniques for structural health monitoring in aircraft structures. We also highlight recent power-supply methods using Power-over-POF in order to feed sensors remotely, and we discuss the constraints imposed by connectors on the performance of POF networks in aircrafts.
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Affiliation(s)
- Pedro C. Lallana
- Electronics Technology Department, Universidad Carlos III de Madrid, E-28911 Leganés, Spain;
- Correspondence: (P.C.L.); (C.V.)
| | - Gotzon Aldabaldetreku
- Communications Engineering Department, University of the Basque Country (UPV/EHU), Ingeniero Torres Quevedo 1, E-48013 Bilbao, Spain; (G.A.); (G.D.); (J.Z.)
| | - Alicia López
- GTF, Aragon Institute of Engineering Research (i3A), University of Zaragoza, María de Luna 1, E-50018 Zaragoza, Spain; (A.L.); (J.M.); (M.Á.L.)
| | - David S. Montero
- Electronics Technology Department, Universidad Carlos III de Madrid, E-28911 Leganés, Spain;
| | - Gaizka Durana
- Communications Engineering Department, University of the Basque Country (UPV/EHU), Ingeniero Torres Quevedo 1, E-48013 Bilbao, Spain; (G.A.); (G.D.); (J.Z.)
| | - Javier Mateo
- GTF, Aragon Institute of Engineering Research (i3A), University of Zaragoza, María de Luna 1, E-50018 Zaragoza, Spain; (A.L.); (J.M.); (M.Á.L.)
| | - M. Ángeles Losada
- GTF, Aragon Institute of Engineering Research (i3A), University of Zaragoza, María de Luna 1, E-50018 Zaragoza, Spain; (A.L.); (J.M.); (M.Á.L.)
| | - Joseba Zubia
- Communications Engineering Department, University of the Basque Country (UPV/EHU), Ingeniero Torres Quevedo 1, E-48013 Bilbao, Spain; (G.A.); (G.D.); (J.Z.)
| | - Carmen Vázquez
- Electronics Technology Department, Universidad Carlos III de Madrid, E-28911 Leganés, Spain;
- Correspondence: (P.C.L.); (C.V.)
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Shao B, Zhang W, Zhang P, Chen W. Multi-Parameter Measurement of Rotors Using the Doppler Effect of Frequency-Swept Interferometry. SENSORS (BASEL, SWITZERLAND) 2020; 20:s20247178. [PMID: 33333833 PMCID: PMC7765328 DOI: 10.3390/s20247178] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 12/09/2020] [Accepted: 12/14/2020] [Indexed: 06/12/2023]
Abstract
The Doppler effect of frequency-swept interferometry (FSI) is often seen as an obstacle to the dynamic ranging accuracy. However, the potential of this obstacle is rarely noticed and used. In this paper, by combining the periodical characteristics of the rotational Doppler effect, an FSI-based multi-parameter measurement method for the rotor is proposed. Through the establishment of the rotational Doppler formula of FSI, it is found that the frequency, direct component, and amplitude of the dynamic distance given by FSI can be utilized to estimate the angular velocity, axial clearance, and tilt angle of the rotor, respectively. A rotor platform and a fiber-optic FSI system were constructed, and a series of experiments were carried out to verify the proposed method. The experimental results showed that the relative errors of the measured axial clearance, angular velocity, and tilt angle were less than 3.5%. This work provides a new perspective on the multi-parameter measurement of the rotor and makes it possible to directly perform multi-parameter measurement inside the space-confined rotating machinery as only a single small-size fiber-optic probe is needed.
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Affiliation(s)
- Bin Shao
- Key Laboratory of Optoelectronic Technology and Systems, Ministry of Education, Chongqing University, Chongqing 400044, China; (B.S.); (P.Z.); (W.C.)
| | - Wei Zhang
- Key Laboratory of Optoelectronic Technology and Systems, Ministry of Education, Chongqing University, Chongqing 400044, China; (B.S.); (P.Z.); (W.C.)
- Artificial Intelligence Center, Peng Cheng Laboratory, Shenzhen 518000, China
| | - Peng Zhang
- Key Laboratory of Optoelectronic Technology and Systems, Ministry of Education, Chongqing University, Chongqing 400044, China; (B.S.); (P.Z.); (W.C.)
| | - Weimin Chen
- Key Laboratory of Optoelectronic Technology and Systems, Ministry of Education, Chongqing University, Chongqing 400044, China; (B.S.); (P.Z.); (W.C.)
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Experimental Investigation of Inductive Sensor Characteristic for Blade Tip Clearance Measurement at High Temperature. SENSORS 2019; 19:s19173694. [PMID: 31450693 PMCID: PMC6749453 DOI: 10.3390/s19173694] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Revised: 08/09/2019] [Accepted: 08/20/2019] [Indexed: 11/17/2022]
Abstract
Turbine tip clearance of aero-engine is important to engine performance. Proper tip clearance can reduce the gas leakage over turbine blade tips and improve the engine efficiency of turbo machinery and reduce the fuel consumption. Therefore, accurate tip clearance measurement is essential. The inductive measurement method is one of the non-contact distance measurement methods, which has the characteristics of high sensitivity, fast response speed, and strong anti-interference ability. Based on the principle of inductive sensor measuring tip clearance, the ambient temperature change may cause the material electromagnetic performance change for the conductivity and permeability varies with temperature. In order to verify the temperature effect on the sensor performance, the repeated calibration experiments were carried out to obtain the sensor repeatability error of 5.4%. Then, the sensor was calibrated in the range of 0mm-4mm clearance at temperature from 600 °C to 1000 °C and obtained the measurement error of 4.6%. Results indicate when the temperature ranged from 600 °C to 1000 °C, clearance measurement error is smaller than the sensor repeatability error so the temperature effect on the sensor characteristics can be ignored. This conclusion makes the sensor promising for monitoring the blade tip clearances at various temperature environment.
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Fernández-Bello R, Amorebieta J, Beloki J, Aldabaldetreku G, García I, Zubia J, Durana G. Performance Comparison of Three Fibre-Based Reflective Optical Sensors for Aero Engine Monitorization. SENSORS 2019; 19:s19102244. [PMID: 31096612 PMCID: PMC6567319 DOI: 10.3390/s19102244] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Revised: 05/07/2019] [Accepted: 05/11/2019] [Indexed: 11/29/2022]
Abstract
Among the different available optical technologies, fibre bundle-based reflective optical sensors represent an interesting alternative for parameter monitorization in aero engines. Tip clearance is one of the parameters of great concern for engine designers and engineers. In the framework of this optical technology, three fibre-based reflective optical sensors have been compared. Two of them are custom designed and based on the same geometrical fibre arrangement, whereas the third one is commercially available and relies on a different geometrical arrangement of the fibres. Their performance has been compared in clearance measurements carried out during an experimental program followed at a transonic wind tunnel for aero turbines. The custom-designed solution that operates in the most sensitive part of its response curve proved to be by far the most reliable tool for clearance measurements. Its high resolution opens up the possibility to detect small blade features such as cracks, reflectivity changes, etc. that otherwise could not be tracked. These results show that the detection of unexpected features on blade tips may have an important effect on how the clearance is calculated, ultimately giving rise to corrective actions.
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Affiliation(s)
- Rubén Fernández-Bello
- Communications Engineering Department, University of the Basque Country UPV/EHU, Ingeniero Torres Quevedo Plaza 1, E-48013 Bilbao, Spain.
| | - Josu Amorebieta
- Communications Engineering Department, University of the Basque Country UPV/EHU, Ingeniero Torres Quevedo Plaza 1, E-48013 Bilbao, Spain.
| | - Josu Beloki
- Fundación Centro de Tecnologías Aeronáuticas (CTA), Bizkaia Technological Park, E-48170 Zamudio, Spain.
| | - Gotzon Aldabaldetreku
- Communications Engineering Department, University of the Basque Country UPV/EHU, Ingeniero Torres Quevedo Plaza 1, E-48013 Bilbao, Spain.
| | - Iker García
- AOTECH, Advanced Optical Technologies S.L., E-48002 Bilbao, Spain.
| | - Joseba Zubia
- Communications Engineering Department, University of the Basque Country UPV/EHU, Ingeniero Torres Quevedo Plaza 1, E-48013 Bilbao, Spain.
| | - Gaizka Durana
- Communications Engineering Department, University of the Basque Country UPV/EHU, Ingeniero Torres Quevedo Plaza 1, E-48013 Bilbao, Spain.
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Eddy Current Sensor System for Blade Tip Clearance Measurement Based on a Speed Adjustment Model. SENSORS 2019; 19:s19040761. [PMID: 30781805 PMCID: PMC6412639 DOI: 10.3390/s19040761] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Revised: 01/26/2019] [Accepted: 02/07/2019] [Indexed: 12/03/2022]
Abstract
Blade tip clearance (BTC) measurement and active clearance control (ACC) are becoming crucial technologies in aero-engine health monitoring so as to improve the efficiency and reliability as well as to ensure timely maintenance. Eddy current sensor (ECS) offers an attractive option for BTC measurement due to its robustness, whereas current approaches have not considered two issues sufficiently. One is that BTC affects the response time of a measurement loop, the other is that ECS signal decays with increasing speed. This paper proposes a speed adjustment model (SAM) to deal with these issues in detail. SAM is trained using a nonlinear regression method from a dynamic training data set obtained by an experiment. The Levenberg–Marquardt (LM) algorithm is used to estimate SAM characteristic parameters. The quantitative relationship between the response time of ECS measurement loop and BTC, as well as the output signal and speed are obtained. A BTC measurement method (BTCMM) based on the SAM is proposed and a geometric constraint equation is constructed to assess the accuracy of BTC measurement. Experiment on a real-time BTC measurement during the running process for a micro turbojet engine is conducted to validate the BTCMM. It is desirable and significative to effectively improve BTC measurement accuracy and expand the range of applicable engine speed.
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Zhao Z, Liu Z, Lyu Y, Gao Y. Experimental Investigation of High Temperature-Resistant Inductive Sensor for Blade Tip Clearance Measurement. SENSORS 2018; 19:s19010061. [PMID: 30586916 PMCID: PMC6338999 DOI: 10.3390/s19010061] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Revised: 12/19/2018] [Accepted: 12/20/2018] [Indexed: 11/24/2022]
Abstract
Turbine tip clearance of aero-engine is important to engine performance. Proper control of rotor tip clearance contributes to engine efficiency improvement and fuel consumption reduction. Therefore, accurate tip clearance measurement is essential. The inductive measurement method is one of the non-contact distance measurement methods, which has the characteristics of high sensitivity, fast response speed and strong anti-interference ability. Based on the principle of inductive sensor measuring tip clearance, the ambient temperature change will cause the material electromagnetic performance change for the conductivity and permeability varies with temperature. The calibration experiment was conducted to obtain the sensor resolution and sensing range. The effect of temperature on sensor parameters was extracted from high temperature experiment data. Results show the resolution of planar coil made of platinum wire can be 10 μm and the maximum sensing range can reach 5 mm. At temperature from 500 ℃ to 1100 ℃, coil inductance almost does not change with temperature while coil resistance varies exponentially with temperature, that means the coil inductance variation can reflect the tip clearance change and resistance can indicate the measuring temperature.
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Affiliation(s)
- Ziyu Zhao
- School of Power and Energy, Northwestern Polytechnical University, Youyi West Road 127#, Xi'an 710054, China.
| | - Zhenxia Liu
- School of Power and Energy, Northwestern Polytechnical University, Youyi West Road 127#, Xi'an 710054, China.
| | - Yaguo Lyu
- School of Power and Energy, Northwestern Polytechnical University, Youyi West Road 127#, Xi'an 710054, China.
| | - Yajun Gao
- School of Power and Energy, Northwestern Polytechnical University, Youyi West Road 127#, Xi'an 710054, China.
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A Novel Method for the Micro-Clearance Measurement of a Precision Spherical Joint Based on a Spherical Differential Capacitive Sensor. SENSORS 2018; 18:s18103366. [PMID: 30304804 PMCID: PMC6210709 DOI: 10.3390/s18103366] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/15/2018] [Revised: 10/02/2018] [Accepted: 10/05/2018] [Indexed: 11/16/2022]
Abstract
A spherical joint is a commonly used mechanical hinge with the advantages of compact structure and good flexibility, and it becomes a key component in many types of equipment, such as parallel mechanisms, industrial robots, and automobiles. Real-time detection of a precision spherical joint clearance is of great significance in analyzing the motion errors of mechanical systems and improving the transmission accuracy. This paper presents a novel method for the micro-clearance measurement with a spherical differential capacitive sensor (SDCS). First, the structure and layout of the spherical capacitive plates were designed according to the measuring principle of capacitive sensors with spacing variation. Then, the mathematical model for the spatial eccentric displacements of the ball and the differential capacitance was established. In addition, equipotential guard rings were used to attenuate the fringe effect on the measurement accuracy. Finally, a simulation with Ansoft Maxwell software was carried out to calculate the capacitance values of the spherical capacitors at different eccentric displacements. Simulation results indicated that the proposed method based on SDCS was feasible and effective for the micro-clearance measurement of the precision spherical joints with small eccentricity.
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Durana G, Amorebieta J, Fernandez R, Beloki J, Arrospide E, Garcia I, Zubia J. Design, Fabrication and Testing of a High-Sensitive Fibre Sensor for Tip Clearance Measurements. SENSORS 2018; 18:s18082610. [PMID: 30096928 PMCID: PMC6111710 DOI: 10.3390/s18082610] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Revised: 08/02/2018] [Accepted: 08/02/2018] [Indexed: 11/23/2022]
Abstract
A highly sensitive fibre bundle-based reflective optical sensor has been designed and fabricated for Tip Clearance measurements in a turbine rig. The sensor offers high spatial and temporal resolution. The sensor probe consists of a single-mode transmitting fibre and two concentric rings of receiving multimode fibres that collect reflected light in a differential detection gain configuration, yielding a highly linear calibration curve for distance measurements. The clearance measurement range is approximately 2 mm around the central point fixed at 3.2 mm from the probe tip, and the sensitivity of the probe is 61.73 mm−1. The fibre bundle has been designed to ensure that the distance security specifications required for the experimental program of the turbine are met. The optical sensor has operated under demanding conditions set by the blade and casing design. The experimental results obtained so far are promising and lead us to think that the optical sensor has great potential for online clearance measurements with high precision.
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Affiliation(s)
- Gaizka Durana
- Communications Engineering Department, University of the Basque Country (UPV/EHU), Ingeniero Torres Quevedo Plaza 1, E-48013 Bilbao, Spain.
| | - Josu Amorebieta
- Communications Engineering Department, University of the Basque Country (UPV/EHU), Ingeniero Torres Quevedo Plaza 1, E-48013 Bilbao, Spain.
| | - Ruben Fernandez
- Communications Engineering Department, University of the Basque Country (UPV/EHU), Ingeniero Torres Quevedo Plaza 1, E-48013 Bilbao, Spain.
| | - Josu Beloki
- Aeronautical Technologies Centre, Bizkaia Technological Park, E-48170 Zamudio, Spain.
| | - Eneko Arrospide
- Applied Mathematics Department, University of the Basque Country (UPV/EHU), Ingeniero Torres Quevedo Plaza 1, E-48013 Bilbao, Spain.
| | - Iker Garcia
- Communications Engineering Department, University of the Basque Country (UPV/EHU), Ingeniero Torres Quevedo Plaza 1, E-48013 Bilbao, Spain.
| | - Joseba Zubia
- Communications Engineering Department, University of the Basque Country (UPV/EHU), Ingeniero Torres Quevedo Plaza 1, E-48013 Bilbao, Spain.
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Optical Tip Clearance Measurements as a Tool for Rotating Disk Characterization. SENSORS 2017; 17:s17010165. [PMID: 28098845 PMCID: PMC5298738 DOI: 10.3390/s17010165] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Revised: 01/05/2017] [Accepted: 01/10/2017] [Indexed: 11/17/2022]
Abstract
An experimental investigation on the vibrational behavior of a rotating disk by means of three optical fiber sensors is presented. The disk, which is a scale model of the real disk of an aircraft engine, was assembled in a wind tunnel in order to simulate real operation conditions. The pressure difference between the upstream and downstream sides of the disk causes an airflow that might force the disk to vibrate. To characterize this vibration, a set of parameters was determined by measuring the tip clearance of the disk: the amplitude, the frequency and the number of nodal diameters in the disk. All this information allowed the design of an upgraded prototype of the disk, whose performance was also characterized by the same method. An optical system was employed for the measurements, in combination with a strain gauge mounted on the disk surface, which served to confirm the results obtained. The data of the strain gauge coincided closely with those provided by the optical fiber sensors, thus demonstrating the suitability of this innovative technique to evaluate the vibrational behavior of rotating disks.
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