Aeronautical Technologies Center

Zamudio, Spain

Aeronautical Technologies Center

Zamudio, Spain
SEARCH FILTERS
Time filter
Source Type

Garcia I.,University of the Basque Country | Beloki J.,Aeronautical Technologies Center | Zubia J.,University of the Basque Country | Durana G.,University of the Basque Country | Aldabaldetreku G.,University of the Basque Country
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2013

Traditional limitations of capacitive, inductive or discharging probe sensor for tip timing and tip clearance measurements are overcome by reflective intensity modulated optical fiber sensors. This paper presents the signals and results corresponding to a one stage turbine rig which rotor has 146 blades, obtained from a transonic wind-tunnel test. The probe is based on a trifurcated bundle of optical fibers that is mounted on turbine casing. It is composed of a central illuminating fiber that guides the light from a laser to the turbine blade, and two concentric rings of receiving fibers that collect the reflected light. Two photodetectors turn this reflected light signal from the receiving rings into voltage. The electrical signals are acquired and saved by a high-sample-rate oscilloscope. In tip clearance calculations the ratio of the signals provided by each ring of receiving fibers is evaluated and translated into distance. In the case of tip timing measurements, only one of the signals is considered to get the arrival time of the blade. The differences between the real and theoretical arrival times of the blades are used to obtain the deflections amplitude. The system provides the travelling wave spectrum, which presents the average vibration amplitude of the blades at a certain nodal diameter. The reliability of the results in the turbine rig testing facilities suggests the possibility of performing these measurements in real turbines under real working conditions. © 2013 SPIE.


Garcia I.,University of the Basque Country | Zubia J.,University of the Basque Country | Berganza A.,University of the Basque Country | Beloki J.,Aeronautical Technologies Center | And 5 more authors.
Journal of Lightwave Technology | Year: 2015

Tip clearance is critical to the performance of rotating turbomachinery. The objective of this paper is to develop a noncontact sensor with a precision of 30 μm to measure tip clearance in a turbine rig assembled in a wind tunnel. To carry out the measurements, an optical sensor whose main component is a bundle of optical fibers is employed. We use four different configurations of this sensor, which are tested in two distinct turbines with the aim of minimizing the effect of the noise on the repeatability of the measurements. Each configuration serves to increase the precision until the required performance is achieved for the measurement of the tip clearance. Our results may be helpful to develop applications related to structural health monitoring or active clearance-control systems. © 2015 IEEE.


Zubia J.,University of the Basque Country | Garcia I.,University of the Basque Country | Berganza A.,University of the Basque Country | Beloki J.,Aeronautical Technologies Center | And 2 more authors.
International Conference on Transparent Optical Networks | Year: 2014

For the last few years, we have been carrying out tip-clearance (TC) measurements in turbine rigs using optical sensors in collaboration with the Aeronautical Technologies Center. Several turbines with completely different blade profiles have been tested with satisfying results. The reflective intensity-modulated sensor used in these tests is based on a trifurcated bundle of optical fibers. This sensor is the ideal candidate for TC measurements because of its low cost, simplicity, robustness and the capability of performing tip-timing measurements (TT) employing the same probe. In the case of TC measurements, the main requirement is a precision of at least 30 μm. In order to get this precision, the latest improvements of the sensor have been focused on reducing the modal noise at the endface of the transmitting fiber of the bundle. For this purpose, different approaches were developed using mode-scramblers, plastic optical fibers and a single-mode illuminating fiber. The results obtained in the tests demonstrate that it is possible to achieve the demanded precision. Hence, in next test campaign, three sensors will be used to determine clearance at three different points of a rotating disk that belongs to a real aircraft engine. © 2014 IEEE.


Garcia I.,University of the Basque Country | Zubia J.,University of the Basque Country | Beloki J.,Aeronautical Technologies Center | Aldabaldetreku G.,University of the Basque Country | And 4 more authors.
International Conference on Transparent Optical Networks | Year: 2015

An experimental study about the vibrational behaviour of two prototypes of a rotating disk by means of three optical sensors is presented. Both prototypes were assembled in a wind tunnel in order to reproduce real operation conditions. The optical sensors identified the vibration frequency and the nodal diameter of the first prototype by measuring the clearance of the disk to the casing of the wind tunnel. This method was also employed to check the improvements obtained with an upgraded design of the rotating disk, showing that the measuring system presents a great potential to perform non-contact evaluation of rotating components. © 2015 IEEE.


Durana G.,University of the Basque Country | Gomez J.,University of the Basque Country | Aldabaldetreku G.,University of the Basque Country | Zubia J.,University of the Basque Country | And 2 more authors.
IEEE Sensors Journal | Year: 2012

We demonstrate the feasibility of long-period gratings (LPGs) written in microstructured polymer optical fibers (mPOFs) for detecting and measuring the strain rate and magnitude of engineering structures. We validate and compare the results of our experimental tests to a commercial fiber Bragg grating sensor. The encouraging results open the way to the use of LPG mPOF sensors in structural health monitoring applications. © 2012 IEEE.


Garcia I.,University of the Basque Country | Zubia J.,University of the Basque Country | Beloki J.,Aeronautical Technologies Center | Arrue J.,University of the Basque Country | And 2 more authors.
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2015

The results of an experimental investigation on the vibrational behaviour of a rotating disk are reported. This disk is a prototype that simulates a component of an aircraft engine. The air flow through the gap between the edge of the disk and the casing, produced because of the pressure difference between the upstream and downstream parts of the disk, might force the disk to flutter under certain circumstances. This situation is simulated in a wind tunnel. The main goal of the tests is to evaluate the vibrational behaviour of a rotating disk, obtaining the correspondence between the vibration frequencies of the disk and the pressure differences when the disk is rotating at diverse speeds. An innovative noncontact technique is utilised, which employs three optical sensors that are angularly equidistributed on the casing of the wind tunnel. In order to verify the results given by the optical sensors, a strain gauge was mounted on the surface of the rotating disk. The results show a perfect agreement between the vibration frequencies detected by both kinds of sensors, proving that the combination of both allows the calculation of the nodal diameter corresponding to the vibration of the disk. © 2015 SPIE.


Montero A.,Aeronautical Technologies Center | de Ocariz I.S.,Aeronautical Technologies Center | Lopez I.,Aeronautical Technologies Center | Venegas P.,Aeronautical Technologies Center | And 2 more authors.
Sensors | Year: 2011

This paper studies the feasibility of calculating strains in aged F114 steel specimens with Fiber Bragg Grating (FBG) sensors and infrared thermography (IT) techniques. Two specimens have been conditioned under extreme temperature and relative humidity conditions making comparative tests of stress before and after aging using different adhesives. Moreover, a comparison has been made with IT techniques and conventional methods for calculating stresses in F114 steel. Implementation of Structural Health Monitoring techniques on real aircraft during their life cycle requires a study of the behaviour of FBG sensors and their wiring under real conditions, before using them for a long time. To simulate aging, specimens were stored in a climate chamber at 70 °C and 90% RH for 60 days. This study is framed within the Structural Health Monitoring (SHM) and Non Destructuve Evaluation (NDE) research lines, integrated into the avionics area maintained by the Aeronautical Technologies Centre (CTA) and the University of the Basque Country (UPV/EHU). © 2011.


Garcia I.,University of the Basque Country | Zubia J.,University of the Basque Country | Berganza A.,University of the Basque Country | Beloki J.,Aeronautical Technologies Center | And 2 more authors.
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2014

The influence of the tip clearance on the performance of rotating turbo machinery is well known. The objective of this work was to measure this parameter using a non-contact sensor with a precision of 30 μm in a real turbine. An optical sensor whose main component is a bundle of optical fibers was selected to carry out the measurements. Three different configurations of the sensor have been tested by taking measurements on two distinct turbines. Tip-clearance measurements are achieved with the desired precision, providing the opportunity to develop applications related to structural health monitoring or active clearance-control systems. © 2014 SPIE.


Montero A.,Aeronautical Technologies Center | Aldabaldetreku G.,University of the Basque Country | Durana G.,University of the Basque Country | Jorge I.,Aeronautical Technologies Center | And 2 more authors.
Advances in Materials Science and Engineering | Year: 2014

We demonstrate the influence of the relative humidity (RH) on the wavelength of fiber Bragg grating sensors (FBGS), performing tests with five FBGS at different humidity and temperature conditions. These tests were performed in a climate chamber whose RH changes according to a scheduled profile from 30% to 90%, in steps of 10%. These profiles were repeated for a wide range of temperatures from 10°C to 70°C, in steps of 10°C. Two different types of instrumentation methods have been tested, spot welding and epoxy bonding, in two different materials, steel and carbon fiber reinforced polymer (CFRP). We discuss the results for each type of sensor and instrumentation method by analyzing the linearity of the Bragg wavelength with RH and temperature. © 2014 Ander Montero et al.


PubMed | University of the Basque Country and Aeronautical Technologies Center
Type: Journal Article | Journal: Sensors (Basel, Switzerland) | Year: 2017

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.

Loading Aeronautical Technologies Center collaborators
Loading Aeronautical Technologies Center collaborators