Hostname: page-component-cd9895bd7-gvvz8 Total loading time: 0 Render date: 2024-12-26T23:07:36.766Z Has data issue: false hasContentIssue false

Experimental investigation of air bearings dynamic coefficients

Published online by Cambridge University Press:  15 November 2010

Get access

Abstract

The paper presents the experimental work developed by the authors for the identification of rotordynamic coefficients of air bearings. Air bearings work at very high rotation speeds and are known to have nonlinear dynamic characteristics depending at least on the excitation frequency. The paper presents two very similar test rigs, the testing procedure and the algorithm for identifying the rotordynamic coefficients. The test rigs consist of a rigid rotor guided by fixed bearings and driven by a spindle. The dynamic loads are applied by two orthogonally mounted shakers applying two linear independent excitations. Two air bearings are analysed in the present paper. The test procedure is first developed for a simple circular bearing with easily predictable dynamic characteristics. Its rotordynamic coefficients are identified by using a least square procedure based on rational functions. The coefficients are compared to theoretical results in order to underline the limits of the identification algorithm. The procedure is next applied to a first generation foil bearing. Rotordynamic coefficients are presented for different working conditions (static loads and rotation speeds) and are discussed comparing them to circular air bearings.

Type
Research Article
Copyright
© AFM, EDP Sciences 2010

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

S. Le Lez, Caractéristiques Statiques et Dynamiques des Paliers à Feuilles, Thèse de Doctorat, Université de Poitiers, 2007
Heshmat, H., Walowit, J., Pinkus, O., Analysis of Gas-Lubricated Compliant Journal Bearings, ASME J. Lubr. Tech. 105 (1983) 647655 CrossRefGoogle Scholar
Carpino, M., Talmage, G., Prediction of Rotor Dynamic Coefficients in Gas Lubricated Foil Journal Bearings with Corrugated Sub-Foils, STLE Tribol. Trans. 49 (2006) 400409 CrossRefGoogle Scholar
L. San Andrés, T.H. Kim, Improvements to the Analysis of Gas Foil Bearings Integration of Top Foil 1d and 2d Structural Models, GT2007-27249, 2007
Le Lez, S., Arghir, M., Frêne, J., Nonlinear Numerical Prediction of Gas Foil Bearings Stability and Unbalanced Response, ASME J. Eng. Gas Turbines Power 131 (2009) 01250312 CrossRefGoogle Scholar
G. Grau, Paliers aérodynamiques radiaux à structure à feuilles: Contribution à l’étude statique et comportement dynamique non linéaire, Thèse de doctorat, INSA de Lyon, 2004
B. Ertas, M. Drexel, J. Van Dam, D. Hallman, A General Purpose Test Facility for Evaluating Gas Lubricated Journal Bearings, The 12th International Symposium on Transport Phenomena and Dynamics of Rotating Machinery, ISROMAC12-2008-20207, 2008
B. Ertas, Compliant Hybrid Journal Bearings Using Integral Wire Mesh Dampers, GT2008-50984, 2008
L. Rudloff, M. Arghir, O. Bonneau, P. Matta, Experimental Analysis of a First Generation Foil Bearing, Start-up Torque and Dynamic Coefficients, Proceedings of ASME Turbo Expo, GT2010-22966, 2010
Matta, P., Arghir, M., Bonneau, O., Experimental Analysis of Cylindrical Air Bearing Dynamic Coefficients, Tribology Trans. 53 (2009) 329339 CrossRefGoogle Scholar
Rouvas, C., Childs, D.W., A Parameter Identification Method for the Rotordynamic Coefficients of a High Reynolds Number Hydrostatic Bearing, ASME J. Vib. Acoust. 115 (1993) 264270 CrossRefGoogle Scholar
San Andrés, L., Diaz, S., A Method for Identification of Bearing Force Coefficients and its Application to a Squeeze Film Damper With a Bubbly Lubricant, Tribology Trans. 42 (1999) 739746 Google Scholar
M. Arghir, P. Matta, Compressibility effects on the dynamic characteristics of gas lubricated mechanical components, C. R. Mecanique (2009), doi:10.1016/j.crme.2009.09.002 CrossRef
N. Geerts, Linear Dynamic Analysis of Rotorsystems with Gas Bearings, Master’s thesis WFW-report 95.090, WFW, Faculty of Mechanical Engineering, Eindhoven University of Technology, 1995
J.W. Roblee, Design of Externally Pressurized Gas Bearings for Dynamic Applications, Ph.D. Thesis, University of California, Berkley, CA, 1985
San Andrés, L., Fluid Compressibility Effects on the Dynamic Response of Hydrostatic J. Bearings, Wear 146 (1991) 269283 CrossRefGoogle Scholar
Kleynhans, G., Childs, D., The Acoustic Influence of Cell Depth on the Rotordynamic Characteristics of Smooth-Rotor/Honeycomb-Stator Annular Gas Seals, ASME J. Eng. Gas Turbines Power 119 (1997) 949957 CrossRefGoogle Scholar
Fourka, M., Tian, Y., Bonis, M., Prediction of the stability of air thrust bearings by numerical, analytical and experimental methods, Wear 198 (1998) 16 CrossRefGoogle Scholar
P. Matta, Analyse Expérimentale des Paliers Aérodynamiques, thèse de Doctorat, Université de Poitiers, 2009