Assessment of the boundary conditions influence on the design load capacity value of the turbocharger gas-dynamic radial foil bearings

Gas-dynamic foil bearings found application in various industries, where oil-free high-speed low-power systems with the long overhaul intervals are required. These bearings are able to operate over a wide range of operating temperatures and could be used in turboexpanders, refrigeration compressors, and high-temperature compressors or micro gas turbine systems. Developing the new, more accurate computation methods for promising designs of this type of bearing still remains relevant. Computational study of the gas flow process in a changing gap between the rotating surface of the high-speed turbomachine rotor and the supporting surface of the radial gas-dynamic foil bearing was performed under various boundary conditions. Gas flow processes in the gas-dynamic bearing gap were simulated at different thicknesses of the gas film. An example of numerical simulation of the foil bearing wedge-shaped gap with a simplified geometric shape formed by eccentric cylindrical surfaces is provided to obtain the working medium surface pressure distribution over the supporting surface under the gas forces action and its load capacity for various boundary conditions. The results obtained made it possible to evaluate the boundary conditions influence on the design load capacity of a gas-dynamic bearing and determine the limits of their applicability for different thicknesses of the gas film.
EDN: TZHYTQ, https://elibrary/tzhytq

References

[1] Agrawal G. Foil air/gas bearing technology — an overview. ASME 1997 Int. Gas Turbine and Aeroengine Congress and Exhibition, 1997, paper no. 97-GT-347, doi: https://doi.org/10.1115/97-GT-347

[2] Dellacorte C., Lukaszewicz V., Valco M.J. et al. Performance and durability of high temperature foil air bearings for oil-free turbomachinery. Tribol. Trans., 2000, vol. 43, no. 4, pp. 774–780, doi: https://doi.org/10.1080/10402000008982407

[3] Bruckner R.J. An assessment of gas foil bearing scalability and the potential benefits to civilian turbofan engines. ASME Turbo Expo, 2010, paper no. GT2010-22118, pp. 29–35, doi: https://doi.org/10.1115/GT2010-22118

[4] Filippova S.P., Dil’mana M.D., Ionov M.S. Demand of the power industry of russia for gas turbines: the current state and prospects. Therm. Eng., 2017, vol. 64, no. 11, pp. 829–840, doi: https://doi.org/10.1134/S0040601517110052

[5] Xiong L.-Y., Wu G., Hou Y. et al. Development of aerodynamic foil journal bearings for a high speed cryogenic turboexpander. Cryogenics, 1997, vol. 37, no. 4, pp. 221–230, doi: https://doi.org/10.1016/s0011-2275(97)00012-x

[6] Sim K., Lee Y.-B., Kim T.H. Rotordynamic analysis of an oil-free turbocharger supported on lobed gas foil bearings—predictions versus test data. Tribol. Trans., 2014, vol. 57, no. 6, pp. 1086–1095, doi: https://doi.org/10.1080/10402004.2014.937885

[7] Walton J.F., Tomaszewski M.J., Heshmat H. The role of high performance foil bearings in advanced, oil-free, high-speed motor driven compressors. 1st Int. Conf. on Fuel Cell Science, Engineering and Technology, 2003, paper no. FUELCELL2003-1747, pp. 411–417, doi: https://doi.org/10.1115/fuelcell2003-1747

[8] DellaCorte C., Bruckner R.J. Remaining technical challenges and future plans for oil-free turbomachinery. J. Eng. Gas Turbines Power, 2011, vol. 133, no. 4, art. 042502, doi: https://doi.org/10.1115/1.4002271

[9] Lubell D., DellaCorte C., Stanford M. Test evolution and oil-free engine experience of a high temperature foil air bearing coating. ASME Turbo Expo, 2006, paper no. GT2006-90572, pp. 1245–1249, doi: https://doi.org/10.1115/gt2006-90572

[10] Luchin G.A., Peshti Yu.V., Snopov A.I. Gazovye opory turbomashin [Gas supports for turbomachines]. Moscow, Mashinostroenie Publ., 1989. 238 p. (In Russ.).

[11] DellaCorte C., Radil K.C., Bruckner R.J. et al. A preliminary foil gas bearing performance map. 2006 Annual Meeting and Exhibition. Report NASA/TM—2006-214343.

[12] Howard S.A., San Andreés L. A new analysis tool assessment for rotordynamic modeling of gas foil bearings. J. Eng. Gas Turbines Power, 2011, vol. 133, no. 2, art. 022505, doi: https://doi.org/10.1115/1.4001997

[13] Bruckner R.J., Puleo B.J. Compliant foil journal bearing performance at alternate pressures and temperatures. ASME Turbo Expo, 2008, paper no. GT2008-50174, pp. 587–594, doi: https://doi.org/10.1115/gt2008-50174

[14] Weissert D.H. Compliant foil fluid film radial bearing. Patent US 5915841. Appl. 05.01.1998, publ. 29.06.1999.

[15] Bosley R.W. Compliant foil hydrodynamic fluid film radial bearing. Patent EP 0756672. Appl. 09.03.1995, publ. 24.06.1998.

[16] Volkov-Muzylev V.V., Borisov Y.A., Pugachuk A.S. et al. Determination of the maximum load capacity of a gas foil journal bearing. Chem. Petrol. Eng., 2021, vol. 57, no. 7–8, pp. 665–671, doi: https://doi.org/10.1007/s10556-021-00990-1