Air foil bearings (AFB’s) are widely used in small to midsized turbomachinery. They are simple in construction, offer very low drag friction, and have very high reliability at high speed operations. This paper presents experimental imbalance response of a 4.84 kg rigid rotor (operating below bending critical speed) supported by two hybrid air foil bearings with 50 mm in diameter. The concept of “hybrid” in this paper utilizes the hydrostatic augmentation of the load capacity during the start up and shut down. The hybrid air foil bearings were designed with three top foils for enhanced stability. Imbalance responses in cylindrical mode are presented up to 44,000rpm with different supply pressures. As the supply pressure is increased from 2.67 to 4 bar, the bearing stiffness increases slightly, resulting in slightly larger vibration (and reduced damping ratio) during the trans-critical speed operation. Hydrodynamic instability was observed with whirl frequency ratios of about 0.17∼0.2 depending on the supply pressures. Tests were also conducted to investigate the effect of supply pressure on the rotordynamic stability. The test results show that the hybrid operation is very effective to suppress the subsynchronous vibrations at high speeds.
Skip Nav Destination
ASME 2011 Turbo Expo: Turbine Technical Conference and Exposition
June 6–10, 2011
Vancouver, British Columbia, Canada
Conference Sponsors:
- International Gas Turbine Institute
ISBN:
978-0-7918-5466-2
PROCEEDINGS PAPER
Imbalance Response of a Rotor Supported by Hybrid Air Foil Bearings Available to Purchase
Daejong Kim,
Daejong Kim
University of Texas at Arlington, Arlington, TX
Search for other works by this author on:
Prajwal Shetty,
Prajwal Shetty
University of Texas at Arlington, Arlington, TX
Search for other works by this author on:
Donghyun Lee
Donghyun Lee
Samsung Electro-Mechanics, Suwon, South Korea
Search for other works by this author on:
Daejong Kim
University of Texas at Arlington, Arlington, TX
Prajwal Shetty
University of Texas at Arlington, Arlington, TX
Donghyun Lee
Samsung Electro-Mechanics, Suwon, South Korea
Paper No:
GT2011-45576, pp. 299-305; 7 pages
Published Online:
May 3, 2012
Citation
Kim, D, Shetty, P, & Lee, D. "Imbalance Response of a Rotor Supported by Hybrid Air Foil Bearings." Proceedings of the ASME 2011 Turbo Expo: Turbine Technical Conference and Exposition. Volume 6: Structures and Dynamics, Parts A and B. Vancouver, British Columbia, Canada. June 6–10, 2011. pp. 299-305. ASME. https://doi.org/10.1115/GT2011-45576
Download citation file:
19
Views
Related Proceedings Papers
Related Articles
Hydrostatic Gas Journal Bearings for Micro-Turbomachinery
J. Vib. Acoust (April,2005)
Design of Three-Pad Hybrid Air Foil Bearing and Experimental Investigation on Static Performance at Zero Running Speed
J. Eng. Gas Turbines Power (December,2010)
Rotordynamic Performance of Flexure Pivot Hydrostatic Gas Bearings for Oil-Free Turbomachinery
J. Eng. Gas Turbines Power (October,2007)
Related Chapters
Summary and Conclusions
Bearing Dynamic Coefficients in Rotordynamics: Computation Methods and Practical Applications
Mechanical Construction
Turbo/Supercharger Compressors and Turbines for Aircraft Propulsion in WWII: Theory, History and Practice—Guidance from the Past for Modern Engineers and Students
Average Shaft Centerline Plots
Fundamentals of Rotating Machinery Diagnostics