Skip to main content

Load Capacity Analysis of Gas Foil Bearing (GFB) for Different Foil Materials

  • Conference paper
  • First Online:
Proceedings of International Conference on Advances in Tribology and Engineering Systems

Part of the book series: Lecture Notes in Mechanical Engineering ((LNME))

  • 1867 Accesses

Abstract

There is a significant attention on GFBs in recent times owing to its oil free technology and suitability over a wide array of operating conditions. However GFBs have considerably low load carrying capacity compared to normal GFBs. The present paper investigated the load capacity of the bump-type GFBs for a simple model considering only deflection of bump foils. The load capacity of GFBs with different foil materials has been inspected in view of comparing the load capacity. Also the variations of GFBs load performance with respect to the compliance of the foil have been reviewed.

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

Access this chapter

Chapter
USD 29.95
Price excludes VAT (USA)
  • Available as PDF
  • Read on any device
  • Instant download
  • Own it forever
eBook
USD 169.00
Price excludes VAT (USA)
  • Available as EPUB and PDF
  • Read on any device
  • Instant download
  • Own it forever
Hardcover Book
USD 219.99
Price excludes VAT (USA)
  • Durable hardcover edition
  • Dispatched in 3 to 5 business days
  • Free shipping worldwide - see info

Tax calculation will be finalised at checkout

Purchases are for personal use only

Institutional subscriptions

Abbreviations

C :

Bearing radial clearance (m)

D :

Diameter of journal (m)

e :

Bearing eccentricity (m)

\( E_{b} \) :

Young’s modulus of bump foil

\( E_{t} \) :

Young’s modulus of top foil \( ({\text{N}}/{\text{m}}^{2} ) \)

\( F_{X} ,F_{Y} \) :

Vertical and horizontal components of hydrodynamic forces (N)

\( \bar{F}_{X} ,\bar{F}_{Y} \) :

Non-dimensional vertical and horizontal components of hydrodynamic forces: \( \frac{{F_{X} }}{{p_{a} R^{2} }}, \frac{{F_{Y} }}{{p_{a} R^{2} }} \)

\( F_{X0} ;F_{Y0} \) :

Vertical and horizontal steady state components of hydrodynamic forces (N)

\( \bar{F}_{X0} ,\bar{F}_{Y0} \) :

Non-dimensional vertical and horizontal steady state components of hydrodynamic forces: \( \frac{{F_{X0} }}{{p_{a} R^{2} }}; \) \( \frac{{F_{Y0} }}{{p_{a} R^{2} }} \)

h :

Film thickness (m)

\( h_{o} \) :

Initial bump height (m)

\( h_{\hbox{min} } \) :

Minimum film thickness (m)

H :

Non-dimensional film thickness

\( H_{\hbox{min} } \) :

Non-dimensional minimum film thickness

i, j :

Grid location in circumferential and axial directions of FDM mesh

\( K_{f} \) :

Bump foil structural stiffness per unit area \( ( {\text{N/m}}^{ 2} ) \)

\( l_{o} \) :

Half bump length (m)

\( l_{s} \) :

Length of segment between the bumps (m)

L:

Bearing length (m)

m :

Number of divisions along j direction of FDM mesh

n :

Number of divisions along i direction of FDM mesh

O :

Centre of bearing

\( O^{\prime} \) :

Centre of journal

\( p \) :

Hydrodynamic pressure in gas film \( ( {\text{N/m}}^{ 2} ) \)

\( p_{a} \) :

Atmospheric pressure in gas film \( ( {\text{N/m}}^{ 2} ) \)

\( \bar{P} \) :

Arithmetic mean pressure along bearing length \( ( {\text{N/m}}^{ 2} ) \)

\( P \) :

Non-dimensional hydrodynamic pressure

\( \bar{p} \) :

Non-dimensional arithmetic mean pressure along bearing length

R :

Radius of journal (m)

s :

Bump foil pitch (m)

\( S \) :

Compliance number: \( \frac{{p_{a} }}{{CK_{f} }} \)

\( t \) :

Time (s)

\( t_{b} \) :

Bump foil thickness (m)

\( t_{t} \) :

Top foil thickness (m)

\( w_{t} \) :

Top foil transverse deflection (m)

\( W \) :

Non-dimensional top foil transverse deflection

\( W_{0} \) :

Steady state load carrying capacity (N)

\( \bar{W}_{0} \) :

Non-dimensional steady state load carrying capacity

\( x,y,z \) :

Coordinate system on the plane of bearing

\( Z \) :

Non-dimensional axial coordinate of bearing: \( \frac{z}{R} \)

\( \alpha \) :

Compliance of the bump foil \( ({\text{m}}^{3} /{\text{N}}):\frac{1}{{K_{f} }} \)

\( \varepsilon \) :

Eccentricity ratio

\( \Uplambda \) :

Bearing number: \( \frac{6\mu \omega }{{p_{a} }}\left( \frac{R}{C} \right)^{2} \)

\( \mu \) :

Gas viscosity \( ( {\text{N - s/m}}^{ 2} ) \)

\( \phi \) :

Attitude angle \( ( {\text{rad)}} \)

\( \theta \) :

Angular coordinate of bearing (rad): \( \frac{x}{R} \)

\( \theta_{o} \) :

Half bump angle (rad)

\( \upsilon \) :

Poisson’s ratio

\( \tau \) :

Non-dimensional time: \( \omega t \)

\( \omega \) :

Rotor angular velocity \( ( {\text{rad/s)}} \)

\( \Updelta \theta ,\Updelta Z \) :

Non-dimensional mesh size of FDM mesh

References

  1. Carpino M (1994) Foil bearing research at Penn state. Department of mechanical engineering the Pennsylvania state University park. N94–23058:148–151

    Google Scholar 

  2. Agrawal GL.1997. Foil air/gas bearing technology—an overview. International Gas Turbine and Aeroengine Congress and Exhibition, Orlando, ASME Paper No. 97-GT-347

    Google Scholar 

  3. Ku CP, Heshmat H (1992) Complaint foil bearing structural stiffness analysis part I: theoretical model—including strip and variable bump foil geometry. ASME J Tribol 114:394–400

    Article  Google Scholar 

  4. Ku CP, Heshmat H (1993) Complaint foil bearing structural stiffness analysis part II: experimental investigation. ASME J Tribol 113:364–369

    Article  Google Scholar 

  5. Heshmat H, Walomit J, Pinkus O (1983) Analysis of gas-lubricated compliant journal bearings. ASME J Lubr Technol 105:647–655

    Article  Google Scholar 

  6. Peng JP, Carpino M (1993) Calculation of stiffness and damping coefficient for elastically supported gas foil bearings. ASME J Tribol 115:20–27

    Article  Google Scholar 

  7. Ku CP, Heshmat H (1994) Structural stiffness and coulomb damping in compliant foil journal bearing: theoretical considerations. STLE Tribol Trans 37:525–533

    Article  Google Scholar 

  8. Agrawal GL (1998) Foil air bearings cleared to land. ASME Mech Eng 120(7): 78–80

    Google Scholar 

  9. DellaCorte C, Fellenstein JA, Benoy P (1999) Evaluation of advanced solid lubricant coatings for foil air bearings operating at 25°C and 500°C. STLE Tribol Trans 42:338–342

    Article  CAS  Google Scholar 

  10. DellaCorte C, Zaldana AR, Radil KC (2004) A systems approach to the solid lubrication of foil air bearings for oil-free turbomachinery. ASME J Tribol 126:200–207

    Article  CAS  Google Scholar 

  11. Peng Z-C, Khonsari MM (2004) On the limiting load-carrying capacity of foil bearings. ASME J Tribol 126:817–818

    Article  Google Scholar 

  12. Kim TH, San Andrés L (2006) Limits for high speed operation of gas foil bearings. ASME J Tribol 128:670–673

    Article  Google Scholar 

  13. DellaCorte C, Valco MJ (2000) Load capacity estimation of foil air journal bearings for oil-free turbomachinery applications. NASA/TM-2000- 209782, ARL-TR-2334

    Google Scholar 

  14. Radil K, Howard S, Dykas B (2002) The role of radial clearance on the performance of foil air bearings. STLE Tribol Trans 45(4):485–490

    Article  CAS  Google Scholar 

  15. Heshmat H (1994) Advancements in the performance of aerodynamic foil journal bearings: high speed and load capacity. ASME J Tribol 116:287–295

    Article  Google Scholar 

  16. Hou Y, Zhu ZH, Chen CZ (2004) Comparative test on two kinds of new compliant foil bearing for small cryogenic turbo-expander. Cryogenics 44:69–72

    Article  CAS  Google Scholar 

  17. Majumdar BC (2008) Introduction to tribology of bearings. S. Chand & Company Ltd, New Delhi

    Google Scholar 

  18. Lez SL, Arghir M, Frene J (2007) A new bump-type foil bearing structure analytical model. ASME J Eng Gas Turb Power 129:1047–1057

    Article  Google Scholar 

  19. Peng Z-C, Khonsari MM (2006) A thermohydrodynamic analysis of foil journal bearings. ASME J Tribol 128:534–541

    Article  CAS  Google Scholar 

  20. Kim TH, San Andrés L (2008) Heavily loaded gas foil bearings: a model anchored to test data. ASME J Eng Gas Turb Power 130:012–504

    Google Scholar 

  21. Lee DH (2010) The effect of coulomb friction on the static performance of foil journal bearings. Elsevier Tribol Int 43:1065–1072

    Article  Google Scholar 

  22. Feng K, Kaneko S (2010) Analytical model of bump-type foil bearings using a link-spring structure and a finite-element shell model. ASME J Tribol 132:021–706

    Article  Google Scholar 

  23. Rubio D, San Andrés L (2006) Bump-type foil bearing structural stiffness: experiments and predictions. ASME J Eng Gas Turb Power 129:494–502

    Article  Google Scholar 

  24. Kim TH, Breedlove AW, San Andrés L (2009) Characterization of a foil bearing structure at increasing temperatures: static load and dynamic force performance. ASME J Tribol 131:041–703

    Article  Google Scholar 

  25. San Andrés L, Rubio D, Kim TH (2007) Rotordynamic performance of a rotor supported on bump type foil gas bearings: experiments and predictions. ASME J Eng Gas Turb Power 129:850–857

    Article  Google Scholar 

  26. San Andrés L, Kim TH (2010) Thermohydrodynamic analysis of bump type gas foil bearings: a model anchored to test data. ASME J Eng Gas Turb Power 132:042–504

    Google Scholar 

  27. San Andrés L, Kim TH (2010) Thermohydrodynamic model predictions and performance measurements of bump-type foil bearing for oil-free turboshaft engines in rotorcraft propulsion systems. ASME J Tribol 132:011–701

    Google Scholar 

  28. Ruscitto D, McCormick J, Gray S (1978) Hydrodynamic air lubricated compliant surface bearing for an automotive gas turbine engine. I-Journal Bearing Performance CONS/9427-1, NASA CR-135368

    Google Scholar 

  29. Tuakta C (2005) Use of fiber reinforced polymer composite in bridge structures. Thesis, Master, Massachusetts Institute of Technology

    Google Scholar 

  30. Chaban V (2011) Strength and structure of carbon–carbon reinforced composite. Department of Chemistry, University of Rochester, Rochester

    Google Scholar 

Download references

Acknowledgments

This work has been carried out in the Department of Mechanical Engineering, Indian Institute of Technology, Guwahati, India, under the supervision of Prof. S. K. Kakoty.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to T. M. Jamir .

Editor information

Editors and Affiliations

Appendix A

Appendix A

$$ K_{1} = H_{i}^{3} (C_{1} + C_{2} ) $$
$$ K_{2} = H_{i}^{3} (C_{3} + C_{4} ) $$
$$ K_{3} = C_{5} + C_{6} - C_{7} $$
$$ C_{1} = \frac{ - 2}{{(\Updelta \theta )^{2} }} $$
$$ C_{2} = \frac{ - 2}{{(\Updelta Z)^{2} }} $$
$$ C_{3} = \frac{{P_{i + 1,j} + P_{i - 1,j} }}{{(\Updelta \theta )^{2} }} $$
$$ C_{4} = \frac{{P_{i,j + 1} + P_{i,j - 1} }}{{(\Updelta Z)^{2} }} $$
$$ C_{5} = \frac{{(P_{i + 1,\,j} + P_{i - 1,\,j} )(P_{i + 1,\,j} H_{i + 1}^{3} + P_{i - 1,\,j} H_{i - 1}^{3} )}}{{4(\Updelta \theta )^{2} }} $$
$$ C_{6} = \frac{{(P_{i,\,j + 1} - P_{i,\,j - 1} )(P_{i,\,j + 1} H_{i}^{3} - P_{i,\,j - 1} H_{i}^{3} )}}{{4(\Updelta Z)^{2} }} $$
$$ C_{7} = \frac{{\Uplambda (P_{i + 1,\,j} H_{i + 1} + P_{i - 1,\,j} H_{i - 1} )}}{2(\Updelta \theta )} $$

Rights and permissions

Reprints and permissions

Copyright information

© 2014 Springer India

About this paper

Cite this paper

Jamir, T.M., Kakoty, S.K. (2014). Load Capacity Analysis of Gas Foil Bearing (GFB) for Different Foil Materials. In: Patel, H., Deheri, G., Patel, H., Mehta, S. (eds) Proceedings of International Conference on Advances in Tribology and Engineering Systems. Lecture Notes in Mechanical Engineering. Springer, New Delhi. https://doi.org/10.1007/978-81-322-1656-8_29

Download citation

  • DOI: https://doi.org/10.1007/978-81-322-1656-8_29

  • Published:

  • Publisher Name: Springer, New Delhi

  • Print ISBN: 978-81-322-1655-1

  • Online ISBN: 978-81-322-1656-8

  • eBook Packages: EngineeringEngineering (R0)

Publish with us

Policies and ethics