Online monitoring of dynamic tip clearance of turbine blades in high temperature environments

Minimized tip clearance reduces the gas leakage over turbine blade tips and improves the thrust and efficiency of turbomachinery. An accurate tip clearance sensor, measuring the dynamic clearances between blade tips and the turbine case, is a critical component for tip clearance control. This paper presents a robust inductive tip clearance sensor capable of monitoring dynamic tip clearances of turbine machines in high-temperature environments and at high rotational speeds. The sensor can also self-sense the temperature at a blade tip in situ such that temperature effect on tip clearance measurement can be estimated and compensated. To evaluate the sensor's performance, the sensor was tested for measuring the tip clearances of turbine blades under various working temperatures ranging from 700 K to 1300 K and at turbine rotational speeds ranging from 3000 to 10 000 rpm. The blade tip clearance was varied from 50 to 2000 µm. The experiment results proved that the sensor can accurately measure the blade tip clearances with a temporal resolution of 10 µm. The capability of accurately measuring the tip clearances at high temperatures (~1300 K) and high turbine rotation speeds (~30 000 rpm), along with its compact size, makes it promising for online monitoring and active control of blade tip clearances of high-temperature turbomachinery.

[1]  Jiang Zhe,et al.  Improving sensitivity of an inductive pulse sensor for detection of metallic wear debris in lubricants using parallel LC resonance method , 2013 .

[2]  Grzegorz Budzik,et al.  Analysis of dimensional accuracy of blade of aircraft engine using a coordinate measuring machine , 2014 .

[3]  Masakatsu Matsuki,et al.  Measurement of blade tip clearance using an ultrasonic sensor , 1997 .

[4]  Hukam Chand Mongia,et al.  Challenges and Progress in Controlling Dynamics in Gas Turbine Combustors , 2003 .

[5]  Bruce M. Steinetz,et al.  High-pressure-turbine clearance control systems: Current practices and future directions , 2004 .

[6]  Jürgen Wilde,et al.  Design optimization of an eddy current sensor using the finite-elements method , 2003, Microelectron. Reliab..

[7]  Jonathan A. DeCastro,et al.  A Study on the Requirements for Fast Active Turbine Tip Clearance Control Systems , 2004 .

[8]  Javier García-Martín,et al.  Non-Destructive Techniques Based on Eddy Current Testing , 2011, Sensors.

[9]  Joan Carletta,et al.  Inductive Coulter counting: detection and differentiation of metal wear particles in lubricant , 2010 .

[10]  Li Du,et al.  A high throughput inductive pulse sensor for online oil debris monitoring , 2011 .

[11]  Jiang Zhe,et al.  A high sensitivity inductive sensor for blade tip clearance measurement , 2014 .

[12]  R. W. Baines,et al.  The research of inhomogeneity in eddy current sensors , 1998 .

[13]  J. Michaels.  Detection, localization and characterization of damage in plates with an in situ array of spatially distributed ultrasonic sensors , 2008 .

[14]  A. K. Skrivervik,et al.  New microwave sensing system for blade tip clearance measurement in gas turbines , 2012, 2012 IEEE Sensors.

[15]  Kevin J. Melcher,et al.  A Reduced Model for Prediction of Thermal and Rotational Effects on Turbine Tip Clearance , 2003 .

[16]  Jean-François Brouckaert,et al.  Unsteady Pressure Measurements With a Fast Response Cooled Probe in High Temperature Gas Turbine Environments , 2011 .

[17]  Lars Büttner,et al.  Turbo machine tip clearance and vibration measurements using a fibre optic laser Doppler position sensor , 2006 .

[18]  Ann P. Dowling,et al.  Acoustic Analysis of Gas Turbine Combustors , 2003 .

[19]  R. L. Kennedy,et al.  LARGE DIAhlETER 718 INGOTS FOR LAND-BASED GAS TURBINES , 2001 .

[20]  Mark R. Woike,et al.  Testing of a Microwave Blade Tip Clearance Sensor at the NASA Glenn Research Center , 2013 .

[21]  Ali Abdul-Aziz,et al.  Turbine Rotor Disk Health Monitoring Assessment Based on Sensor Technology and Spin Tests Data , 2013, TheScientificWorldJournal.

[22]  Radosław Przysowa,et al.  Inductive sensors for blade tip-timing in gas turbines , 2015 .

[23]  Andrei B. Vakhtin,et al.  Optical Probe for Monitoring Blade Tip Clearance , 2009 .

[24]  Peter Jeschke,et al.  Study on Relevant Effects Concerning Heat Transfer of a Convection Cooled Gas Turbine Blade Under Realistic Engine Temperature Conditions , 2013 .

[25]  J. Chivers,et al.  A technique for the measurement of blade tip clearance in a gas turbine , 1989 .

[26]  Richard J Goldstein,et al.  Film cooling on a gas turbine blade near the end wall , 1985 .

[27]  A. von Flotow,et al.  Monitoring blade passage in turbomachinery through the engine case (no holes) , 2002, Proceedings, IEEE Aerospace Conference.

[28]  Fritz B. Prinz,et al.  Capacitive sensor for active tip clearance control in a palm-sized gas turbine generator , 2005, IEEE Transactions on Instrumentation and Measurement.