Skip to main content

Advertisement

Log in

Investigation into the Development and Testing of a Simplex Capacitance Sensor for Rotor Tip Clearance Measurement in Turbo Machinery

  • Published:
Experimental Techniques Aims and scope Submit manuscript

Abstract

The rotor tip clearance is a vital parameter to characterize turbomachinery performance. It is an essential measurement during engine development and testing. The efficiency of the major modules like fan, compressor and turbine depends on the optimum running clearances. The capacitive sensor is preferred for tip clearance measurements because of various inherent advantages. They are fabricated through complex processes for turbomachinery application and are expensive. These sensors are exposed to harsh engine environments and are likely to exhibit degraded performance. Insulation failure at sensing head, connector contamination and micro-cracks in the MI (Mineral Insulated) cable leads to noise in the signal output. Frequent mechanical failures are also seen due to work hardening of MI cables, lead connector detachments and failure of micro fins at interconnects. Fault fixing of these is tedious and very expensive. This paper presents the concerted effort in developing a simple capacitance sensor addressing potential sensor failure issues. The design features include simple construction, ease of sensor assembly, component realization and troubleshooting. The design also addresses all safety requirements. The sensor has a large sensing area (7.6 mm diameter) producing very stable, high-level signal. The developed sensor produces output that varies from 1 VP-P to 11 VP-P for blade-tip gaps between 3 mm to 0.4 mm respectively. Blade pass simulation studies across the sensor, display almost flat response at minimum clearance. This feature results in very minimal data acquisition errors. The sensor along with RC (Resistance-Capacitance) conditioning electronics was successfully used for clearance measurement on fan stage of gas turbine engine. Test results are in line with the predictions. Extensive tip clearance measurements on the engine validate the design. The current work provides an insight into the development of a simplex capacitance sensor for tip clearance measurement.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9
Fig. 10
Fig. 11
Fig. 12
Fig. 13
Fig. 14
Fig. 15
Fig. 16

Similar content being viewed by others

References

  1. Amsbury CR, Chivers JWH (1978) Systems for the measurement of rotor tip clearance and displacement in a gas turbine. AGARD-237, Propulsion and Energetics Panels 51st (B) Specialists meeting, Seal Technology in Gas Turbine Engines, London

  2. Dhadwal HS, Kurkov AP (1999) Dual-laser probe measurement of blade-tip clearance. J Turbomach 121:481–486

    Article  Google Scholar 

  3. Pfister T, Büttner L, Czarske J, Krain H, Schodl R (2006) Turbo machine tip clearance and vibration measurements using a fibre optic laser Doppler position sensor. Meas Sci Technol 17:1693–1705. https://doi.org/10.1088/0957-0233/17/7/007

    Article  CAS  Google Scholar 

  4. Maslovskiy A, Bakulin M, Snitko M (2012) Microwave blade tip clearance measurements: principles, current practices and future opportunities. ASME paper GT2012–69201, proceedings of ASME Turbo expo. Denmark, Copenhagen, p 2012

    Google Scholar 

  5. Tagashira T, Sugiyama N, Matsuda Y, Matsuki M (1997) Measurement of blade tip clearance using an ultrasonic sensor. AIAA Paper 97–0165, in: Proceedings of 35th AIAA Aerospace Sciences Meeting and Exhibit, Reno, NV. https://doi.org/10.2514/6.1997-165

  6. Hall LC, Jones BE (1976) An investigation into the use of a cone-jet sensor for clearance and eccentricity measurement in turbomachinery. Proc Instn Mech Engrs 190:23–30

    Article  Google Scholar 

  7. Hastings MM, Jensen HB (1996) A novel proximity probe unaffected by shaft electromagnetic properties. ASME Paper 96-GT-4, International Gas Turbine and Aeroengine Congress & Exhibition, Birmingham, UK

  8. Drumm M, Haase WC (2000) High performance rotor health monitoring. Transactions of IEEE June 2000, 6.E.4–1 to 6.E.4–8

  9. Barranger JP (1978) An in-place calibration technique to extend the temperature capability of capacitance sensor system. Proceedings of the Society of Automotive Engineers Aerospace Meeting, SAE Paper 781 003, San Diego, CA

  10. Demers RN (1986) Compressor blade clearance measurement using capacitance and phase lock techniques. in: AGARD Advanced Instrumentation Aero Engine Components, Philadelphia, PA, n.b. 399, p 30

  11. Sarma G, Barranger JP (1992) Capacitance-type blade-tip clearance measurement system using a dual amplifier with ramp/DC inputs and integration. IEEE Trans Instrum Meas 41:674–678

    Article  Google Scholar 

  12. Barranger JP (1987) Low-cost FM oscillator for capacitance type of blade tip clearance measurement system. NASA Technical Paper 2746

  13. Chivers J (1989) A technique for the measurement of blade tip clearance in a gas turbine. AIAA 89-2916, Proceedings of the 25th joint propulsion conference

  14. Sheard AG, Killeen B (1995) A blade-by-blade tip clearance measurement system for gas turbine applications. J Eng Gas Turbines Power 117:326–331

    Article  Google Scholar 

  15. Bailleul GD, Albijat S (1996) Review of progress in the development of capacitive sensors for blade tip clearance measurement. ASME Paper 96-TA-1, Proceedings of ASME Turbo Asia Conference, Jakarta, Indonesia

  16. Flotow AV, Mercadal M, Tappert P (2000) Health monitoring and prognostics of blades and disks with blade tip sensors. IEEE Transactions 0–7803–5846-5/00, 433–440

  17. Tomassini R, Rossi G, Brouckaert J-F (2015) Blade tip clearance and blade vibration measurements using a magnetoresistive sensor. Proceedings of 11th European Conference on Turbomachinery Fluid dynamics & Thermodynamics, Madrid, Spain

  18. Rickards C (1992) Electrical capacitance clearance meter. US Patent No 5:101,165

    Google Scholar 

  19. Steiner A (2000) Techniques for blade tip clearance measurements with capacitive probes. Meas Sci Technol 11:865–869

    Article  CAS  Google Scholar 

  20. Lavagnoli S, Paniagua G, Tulkens M, Steiner A (2012) High-fidelity rotor gap measurements in a short-duration turbine rig. Mech Syst Signal Process 27:590–603

    Article  Google Scholar 

  21. Satish TN, Murthy R, Singh AK (2014) Analysis of uncertainties in measurements of rotor blade tip clearance in gas turbine engine under dynamic condition. Proceedings of IMechE-Part G. J Aerosp Eng 228(5):652–670

    Google Scholar 

  22. Müller D, Sheard AG, Mozumdar S, Johann E (1996) Capacitive measurement of compressor and turbine blade tip to casing running clearance. ASME 96-GT-349, International Gas Turbine and Aeroengine Congress & Exhibition, Birmingham, UK

Download references

Acknowledgments

Authors acknowledge the contribution of Mr Azam Alikhan. TOA and Sri Bharath V for creating required CAD models & drawings, staff of BTC group for having captured engine test data, Sri Ajay Pratap Sc G compressor group for his technical advise and suggestions, and the support extended by all staff of Instrumentation and Control Engineering department of GTRE.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to T.N. Satish.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Satish, T., Rao, A., Nambiar, A. et al. Investigation into the Development and Testing of a Simplex Capacitance Sensor for Rotor Tip Clearance Measurement in Turbo Machinery. Exp Tech 42, 575–592 (2018). https://doi.org/10.1007/s40799-018-0281-y

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s40799-018-0281-y

Keywords

Navigation