Abstract
Porous tilting pad bearings (PTPBs) show a potential for using in high-speed, high precision rotating machinery that requires high bearing stiffness and good stability. In this study, the nonlinear characteristics of a rotor supported on PTPBs are investigated. The Darcy equations and the modified Reynolds equations are adopted to establish the gas flow model in porous materials and gas film region, respectively. The pad motions and rotor motions are also included in the numerical nonlinear model. The advantages of PTPBs over tilting pad journal bearings are discussed. PTPBs with externally pressurized gas can avoid friction during startup and shutdown, improve the load capacity at low rotational speeds, and effectively suppress subsynchronous vibrations at high rotational speeds. The nonlinear characteristics of the rotor-bearing system with various bearing parameters, such as supply pressure ratio, nominal bearing clearance, pad tilting and radial stiffness, are analyzed. Poincaré maps, predicted rotor orbit and bifurcation diagrams are used. High supply pressure ratio and small nominal bearing clearance can significantly decrease the orbit size and increase the critical speed. Low tilting and high radial stiffness can improve system stability. This study reveals the complex nonlinear characteristics of the system and provides guidance for designing PTPBs for using in high-speed rotating machinery.
![](http://media.springernature.com/m312/springer-static/image/art%3A10.1007%2Fs11071-018-4431-7/MediaObjects/11071_2018_4431_Fig1_HTML.png)
![](http://media.springernature.com/m312/springer-static/image/art%3A10.1007%2Fs11071-018-4431-7/MediaObjects/11071_2018_4431_Fig2_HTML.png)
![](http://media.springernature.com/m312/springer-static/image/art%3A10.1007%2Fs11071-018-4431-7/MediaObjects/11071_2018_4431_Fig3_HTML.png)
![](http://media.springernature.com/m312/springer-static/image/art%3A10.1007%2Fs11071-018-4431-7/MediaObjects/11071_2018_4431_Fig4_HTML.png)
![](http://media.springernature.com/m312/springer-static/image/art%3A10.1007%2Fs11071-018-4431-7/MediaObjects/11071_2018_4431_Fig5_HTML.png)
![](http://media.springernature.com/m312/springer-static/image/art%3A10.1007%2Fs11071-018-4431-7/MediaObjects/11071_2018_4431_Fig6_HTML.png)
![](http://media.springernature.com/m312/springer-static/image/art%3A10.1007%2Fs11071-018-4431-7/MediaObjects/11071_2018_4431_Fig7_HTML.png)
![](http://media.springernature.com/m312/springer-static/image/art%3A10.1007%2Fs11071-018-4431-7/MediaObjects/11071_2018_4431_Fig8_HTML.png)
![](http://media.springernature.com/m312/springer-static/image/art%3A10.1007%2Fs11071-018-4431-7/MediaObjects/11071_2018_4431_Fig9_HTML.png)
![](http://media.springernature.com/m312/springer-static/image/art%3A10.1007%2Fs11071-018-4431-7/MediaObjects/11071_2018_4431_Fig10_HTML.png)
![](http://media.springernature.com/m312/springer-static/image/art%3A10.1007%2Fs11071-018-4431-7/MediaObjects/11071_2018_4431_Fig11_HTML.png)
![](http://media.springernature.com/m312/springer-static/image/art%3A10.1007%2Fs11071-018-4431-7/MediaObjects/11071_2018_4431_Fig12_HTML.png)
![](http://media.springernature.com/m312/springer-static/image/art%3A10.1007%2Fs11071-018-4431-7/MediaObjects/11071_2018_4431_Fig13_HTML.png)
![](http://media.springernature.com/m312/springer-static/image/art%3A10.1007%2Fs11071-018-4431-7/MediaObjects/11071_2018_4431_Fig14_HTML.png)
![](http://media.springernature.com/m312/springer-static/image/art%3A10.1007%2Fs11071-018-4431-7/MediaObjects/11071_2018_4431_Fig15_HTML.png)
![](http://media.springernature.com/m312/springer-static/image/art%3A10.1007%2Fs11071-018-4431-7/MediaObjects/11071_2018_4431_Fig16_HTML.png)
![](http://media.springernature.com/m312/springer-static/image/art%3A10.1007%2Fs11071-018-4431-7/MediaObjects/11071_2018_4431_Fig17_HTML.png)
![](http://media.springernature.com/m312/springer-static/image/art%3A10.1007%2Fs11071-018-4431-7/MediaObjects/11071_2018_4431_Fig18_HTML.png)
![](http://media.springernature.com/m312/springer-static/image/art%3A10.1007%2Fs11071-018-4431-7/MediaObjects/11071_2018_4431_Fig19_HTML.png)
![](http://media.springernature.com/m312/springer-static/image/art%3A10.1007%2Fs11071-018-4431-7/MediaObjects/11071_2018_4431_Fig20_HTML.png)
![](http://media.springernature.com/m312/springer-static/image/art%3A10.1007%2Fs11071-018-4431-7/MediaObjects/11071_2018_4431_Fig21_HTML.png)
![](http://media.springernature.com/m312/springer-static/image/art%3A10.1007%2Fs11071-018-4431-7/MediaObjects/11071_2018_4431_Fig22_HTML.png)
Similar content being viewed by others
Abbreviations
- W :
-
Pad width (m)
- L :
-
Pad axial length (m)
- \(r_0 ,\;r_d \) :
-
Pad radius and rotor diameter (m)
- \(\Theta _p \) :
-
Pad arc angle (rad)
- \(\theta _s ,\;\theta _e \) :
-
Pad leading edge and pad trailing edge (rad)
- \(\;\theta _p \) :
-
Angular position of pivot (rad)
- \(\delta ,\;\xi \) :
-
Pad radial displacement (m) and pad tilting angle (rad)
- \(m_p ,\;I_p \) :
-
Pad mass (kg) and moment of inertia of pad (kg m\(^{2})\)
- \(p_a ,\;p_s \) :
-
Ambient and supply pressures (pa)
- p :
-
Pressure (pa)
- P :
-
Dimensionless pressure \((p/p_a)\)
- \(r,\;\theta ,\;z\) :
-
Coordinates in the r, \(\theta \), and z directions
- \(R,\;Z\) :
-
Dimensionless coordinates in the r and z directions
- C :
-
Nominal clearance (m)
- \(h,\;H\) :
-
Film thickness (m) and dimensionless film thickness (h / C)
- \(e_x ,\;e_y \) :
-
Components of rotor eccentricity
- \(\omega \) :
-
Angular velocity of shaft (rad/s)
- \(m_\theta ,\;m_r ,\;m_z \) :
-
Mass flow rates in the \(\theta ,\;r\) and z directions
- \(\Delta m_t \) :
-
Varied amount of mass flow rates per unit time
- \(x,\;y\) :
-
x and y axes
- \(F_x ,\;F_y \) :
-
Forces acting on shaft along the x and y axes caused by gas pressure (N)
- \(F_{p\delta } ,\;M_{p\xi } \) :
-
Radial force (N) and tilting moment (N m)
- \(K_\delta \) :
-
Radial stiffness of the straight beam (N/m)
- \(K_\xi \) :
-
Tilting stiffness of the pivot (N m/rad)
- \(\eta \) :
-
Porosity of porous materials
- k :
-
Permeability of porous materials (m\(^{2})\)
- \(\mu ,\;\rho \) :
-
Gas viscosity (Pa s) and density (kg/m\(^{3})\)
- \(\mathfrak {R}\) :
-
Air gas constant (J/kg K)
- T :
-
Temperature of the supply gas (K)
References
Wang, C.C., Chen, C.O.K.A.: Bifurcation analysis of self-acting gas journal bearings. J. Tribol. 123(4), 755–767 (2001)
Wang, C.C.: Nonlinear dynamic behavior and bifurcation analysis of a rigid rotor supported by a relatively short externally pressurized porous gas journal bearing system. Acta Mech. 183(1–2), 41–60 (2006)
Wang, C., Lo, C., Chen, C.O.: Nonlinear dynamic analysis of a flexible rotor supported by externally pressurized porous gas journal bearings. J. Tribol. Trans. Asme 124(3), 553–561 (2002)
Chang-Jian, C.W., Chen, C.O.K.: Chaotic response and bifurcation analysis of a flexible rotor supported by porous and non-porous bearings with nonlinear suspension. Nonlinear Anal. Real World Appl. 10(2), 1114–1138 (2009)
Wang, C.C., Liu, C.C.: Bifurcation and nonlinear dynamic analysis of externally pressurized double air films bearing system. In: Mathematical Problems in Engineering, 2014, (2014-4-27). 2014(3), 759–765 (2014)
Monmousseau, P., Fillon, M.: Frequency effects on the TEHD behavior of a tilting-pad journal bearing under dynamic loading. J. Tribol. 121(2), 321–326 (1999)
Cha, M., Isaksson, P., Glavatskih, S.: Influence of pad compliance on nonlinear dynamic characteristics of tilting pad journal bearings. Tribol. Int. 57(57), 46–53 (2013)
Cha, M., Glavatskih, S.: Nonlinear dynamic behaviour of vertical and horizontal rotors in compliant liner tilting pad journal bearings: some design considerations. Tribol. Int. 82, 142–152 (2015)
Feng, F., Chu, F.: Influence of pre-load coefficient of TPJBs on shaft lateral vibration. Tribol. Int. 35(1), 65–71 (2002)
Ying, J., Jiao, Y., Chen, Z.: Nonlinear dynamics analysis of tilting pad journal bearing-rotor system. Shock Vib. 18(1–2), 45–52 (2015)
Lu, Y., Zhang, Y., Shi, X., Wang, W., Yu, L.: Nonlinear dynamic analysis of a rotor system with fixed-tilting-pad self-acting gas-lubricated bearings support. Nonlinear Dyn. 69(3), 877–890 (2012)
Lu, Y.J., Ji, L.F., Zhang, Y.F., Wu, Y., Liu, Y.Y., Yu, L.: Dynamic behaviours of the rotor non-linear system with fixed-tilting-pad journal bearings support. Proc. Inst. Mech. Eng. Part J J. Eng. Tribol. 1(J10), 1–11 (2010)
Feng, K., Liu, W., Zhao, X., Li, W.: Nonlinear numerical prediction of a rotor-bearing system using damped flexure pivot tilting pad gas bearings. Tribol. Trans. 60(3), 448–459 (2016)
Feng, K., Liu, W., Zhang, Z., Zhang, T.: Theoretical model of flexure pivot tilting pad gas bearings with metal mesh dampers in parallel. Tribol. Int. 94, 26–38 (2015)
San Andrés, L., Cable, T.A., Zheng, Y., De Santiago, O., Devitt, D.: Assessment of porous type gas bearings: measurements of bearing performance and rotor vibrations. 2016(49842), V07BT31A031
Zhu, X., Andres, L.S.: Experimental response of a rotor supported on rayleigh step gas bearings. Proceedings of the ASME Turbo Expo 2005, vol. 4, May 715–724 (2005)
Zhu, X., AndréS, L.S., Zhu, X., AndréS, L.S.: Rotordynamic performance of flexure pivot hydrostatic gas bearings for oil-free turbomachinery. J. Eng. Gas Turbines Power 129(4), 691–699 (2004)
AndréS, L.S.: Hybrid flexure pivot-tilting pad gas bearings: analysis and experimental validation. J. Tribol. 128(3), 551–558 (2006)
Adams, M.L., Payandeh, S.: Self-excited vibration of statically unloaded pads in tilting-pad journal bearings. J. Tribol. 105(3), 377–384 (1983)
Acknowledgements
The authors acknowledge the financial support from the National Natural Science Foundation of China (No. 51575170), The Joint Advance Research Program of equipment, Ministry of Education of China (6141A02033503). Research program supported by Science and Technology Commission of Shanghai Municipality (17DZ1201000), Supported by the fund of the State Key Laboratory of Digital Manufacturing Equipment & Technology in HUST (DMETKF2017012).
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Wu, Y., Feng, K., Zhang, Y. et al. Nonlinear dynamic analysis of a rotor-bearing system with porous tilting pad bearing support. Nonlinear Dyn 94, 1391–1408 (2018). https://doi.org/10.1007/s11071-018-4431-7
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11071-018-4431-7