Journal of Computational & Applied Research in Mechanical Engineering (JCARME)

Document Type : Research Paper

Authors

Malaviya National Institute of Technology, Jaipur, Rajasthan, 302017, India

https://doi.org/10.22061/jcarme.2020.5453.1679

Abstract

The simplified analytical method has developed to analyze the effect of bearing geometrical parameters, i.e. eccentricity ratio, journal rotation speed, slenderness ratio, bearing radial clearance, pad pivot offset and the number of pads on tilting pad journal bearing (TPJB) properties, i.e. fluid film thickness, fluid film forces and fluid film stiffness and damping coefficients of TPJB. Reynolds equation was solved for each pad to determine fluid film pressure on pads. The infinite short bearing assumption used to determine pressure distribution on pads integrated over the pad surface to find fluid film forces. The pressure distribution and fluid film forces validated with previous researches. Error bars presented to indicate accuracy measurement. The maximum error found was not more than 6 percent corresponding to loaded pads. The percentage error found maximum when the eccentricity ratio is 0.25 while it found a minimum when the eccentricity ratio is 0.62. The Matlab code has been developed for the solution of non-linear equations. Results produced in the form of design curves which compares changes in fluid film properties corresponding to TPJB geometric parameters. The results obtained in this manuscript are applicable in other similar researches to find appropriate and limiting values of fluid film properties at different geometrical and parametric conditions. The generated plots and data are helpful in dynamic analysis to find the value of a specific parameter corresponding to a specific value of fluid film coefficient, which makes an easier selection of suitable numerical integration technique and boundary conditions to avoid non-significant results, which save time and effort in the nonlinear analysis.

Graphical Abstract

Keywords

dor

20.1001.1.22287922.2021.10.2.10.1

Main Subjects

Nonlinear Solution

References

[1] D. Timothy, Amir Younan, and Paul Allaire. "A review of tilting pad bearing theory." International Journal of Rotating Machinery(2011).

[2] A. Ghasem, Adnan M., and Dara W. Childs. "Rotordynamic coefficients measurements versus predictions for a high-speed flexure-pivot tilting-pad bearing (load-between-pad configuration)." Journal of engineering for gas turbines and power 128, no. 4, pp. 896-906, (2006).

[3] E. P. Okabe, "Analytical model of a tilting pad bearing including turbulence and fluid inertia effects." Tribology International 114, pp. 245-256, (2017).

[4] J. W. Lund, "Spring and damping coefficients for the tilting-pad journal bearing." ASLE transactions 7, no. 4, pp.342-352, (1964).

[5] J. C. Nicholas, and R. G. Kirk. "Four pad tilting pad bearing design and application for multistage axial compressors." Journal of Lubrication Technology 104, no. 4, pp. 523-529, (1982).

[6] M. F. White, E. Torbergsen, and Victor A. Lumpkin. "Rotordynamic analysis of a vertical pump with tilting-pad journal bearings." Wear 207, no. 1-2, pp. 128-136, (1997).

[7] F. Feng, and F. Chu. "Influence of pre-load coefficient of TPJBs on shaft lateral vibration." Tribology international 35, no. 1, pp. 65-71 (2002).

[8] I. A. Mahfouz, Issam, and Maurice L. Adams. "Numerical study of some nonlinear dynamics of a rotor supported on a three-pad tilting pad journal bearing (TPJB)." Journal of vibration and acoustics 127, no. 3, pp. 262-272, (2005).

[9] E. P. Okabe, Eduardo Paiva, and Katia Lucchesi Cavalca. "Rotordynamic analysis of systems with a non-linear model of tilting pad bearings including turbulence effects." Nonlinear Dynamics 57, no. 4, pp. 481-495, (2009).

[10] E. P. Okabe, "Analytical model of a tilting pad bearing including turbulence and fluid inertia effects." Tribology International 114, pp. 245-256, (2017).

[11] J. Luneno, J. Aidanpaa, and Rolf Gustavsson. "Misalignment in combi-bearing: A cause of parametric instability in vertical rotor systems." Journal of engineering for gas turbines and power 135, No. 3 (2013): 032501.

[12] J. Luneno, Jan-Olov Aidanpaa, and Rolf Gustavsson. "Experimental verification of a combi-bearing model for vertical rotor systems." Journal of Vibration and Acoustics 135,no.3(2013):034501.

[13] M. Nasselqvist, Rolf Gustavsson, and Jan-Olov Aidanpaa. "Experimental and numerical simulation of unbalance response in vertical test rig with tilting-pad bearings." International Journal of Rotating Machinery, (2014).

[14] E. Synnegard, Rolf Gustavsson, and Jan-Olov Aidanpää. "Influence of cross-coupling stiffness in tilting pad journal bearings for vertical machines." International Journal of Mechanical Sciences 111, pp. 43-54, (2016).

[15] E. Khosravian, and S. Ghatreh. "Dynamic Properties of Tilting-Pad Journal Bearings in Power Plant Iran (Yazd Station)." Indian J. Sci. Res. 1, pp. 690, (2014).

[16] E. Khosravian and S. Ghatreh. "Dynamic Properties of Tilting-Pad Journal Bearings in Power Plant Iran (Yazd Station)." Indian J. Sci. Res., Vol. 1, No. 2, pp. 690-701, (2014).

[17] Asgharifard-Sharabiani, Pouya, and Hamid Ahmadian. "Nonlinear model identification of oil-lubricated tilting pad bearings." Tribology International 92, pp. 533-543, (2015).

[17] A. Chasalevris, "Analytical evaluation of the static and dynamic characteristics of three-lobe journal bearings with finite length." J. Tribol., Vol. 137, No. 4, pp. 041701(01-16), (2015).

[18] P. Sharabiani, Pouya and H. Ahmadian, "Nonlinear model identification of oillubricated tilting pad bearings." Tribol. Int., Vol. 92, pp. 533-543, (2015).

[19] Jin, Yingze, Fei Chen, Jimin Xu, and Xiaoyang Yuan. "Nonlinear dynamic analysis of low viscosity fluid-lubricated tilting-pad journal bearing for different design parameters." Friction, pp. 1-15, (2019).

[19] P. Dang, S. Chatterton, P. Pennacchi, A. Vania, and F. Cangioli, "Investigation of load direction on a five-pad tilting pad journal bearing with variable clearance." In Proceedings of the 14th IFToMM World Congress, pp. 503-511, (2015).

[20] Y. Jin, Z. Shi, X. Zhang and X. Yuan, "Rapid solution for analysis of nonlinear fluid film force and dynamic behavior of a tilting-pad journal bearing-rotor system with turbulent and thermal effects." Frict., Vol. 8, No. 2, pp. 343-359, (2020).

[21] Y. Jin, F. Chen, J. Xu, and X. Yuan, "Nonlinear dynamic analysis of low viscosity fluid-lubricated tilting-pad journal bearing for different design parameters." Frict., Vol. 8, No. 5, pp. 930-944, (2020).

[22] E. Ciulli, P. Forte, M. Libraschi, L. Naldi, and M. Nuti, "Characterization of highpower turbomachinery tilting pad journal bearings: First results obtained on a novel test bench." Lubr., Vol. 6, No. 4, pp. 1-15, (2018).

[23] E. Ciulli, and P. Forte, "Nonlinear Response of Tilting Pad Journal Bearings to Harmonic Excitation." Mach., Vol. 7, No. 43, p. 1-14, (2019).

[24] H. Silva and R. Nicoletti, "Design of tilting-pad journal bearings considering bearing clearance uncertainty and reliability analysis." J. Tribol., Vol. 141, No. 1, pp. 1-26, (2019).

[25] L. Andres, B. Koo and M. Hemmi, "A flow starvation model for tilting pad journal bearings and evaluation of frequency response functions: a contribution towards understanding the onset of low frequency shaft motions." In ASME Turbo Expo 2017: Turbomachinery Technical Conference and Exposition. ASME Digital Collection, Vol. 140, No. 1, pp. 052506 (1-14), (2017).

[26] M. Barsanti, E. Ciulli, P. Forte, M. Libraschi and M. Strambi. "Error analysis in the determination of the dynamic coefficients of tilting pad journal bearings." Procedia Struct. Integrity, Vol. 24, No. 1, pp. 988-996, (2019).

[27] M. Barsanti, E. Ciulli and P. Forte, "Random error propagation and uncertainty analysis in the dynamic characterization of Tilting Pad Journal Bearings." J. Phys. Conf. Ser., Vol. 1264, No. 1, pp. 012035(1-11), (2019).

[28] L. R. Ito, D. J. Ramos, Z. de C. Silveira, and G. B. Daniel. "Parametric Sensitivity Analysis of Tilting Pad Bearings to Investigate the Dynamic Behavior of Rotating Machines, " Int. Conf. Rotor Dyn., Vol. 1, No. 1, pp. 292-306, (2018).

[29] I. F. Santos and F. H. Russo, "Tilting-pad journal bearings with electronic radial oil injection." J. Tribol., Vol. 120, No. 3, pp. 583-594, (1998).

[30] J. S. Rao, “Rotor dynamics”, New Age International, pp. 161-196, (1996).

[31] Y. Wang, Y. Gao, Y. Cui and Z. Liu, "Establishment of approximate analytical model of oil film force for finite length tilting pad journal bearings." Int. J. Rotating Mach., Vol. 1, No. 1, pp. 1-11, (2015).

[32] Y. J. Lu, L. F. Ji, Y. F. Zhang, Y. Wu, Y. Y. Liu and L. Yu, "Dynamic behaviours of the rotor non-linear system with fixed—tilting-pad journal bearings support." Proc. Inst. Mech. Eng., Part J: J. Eng. Tribol., Vol. 224, No. 10, pp. 1037-1047, (2010).

Name *

Email Address *

Affiliation *

Comments *

Security Code *

CAPTCHA Image