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Effect of variable viscosity on free flow of non-Newtonian power-law fluids along a vertical surface with thermal stratification

M.B.K. Moorthy K. Senthilvadivu
Archives of Thermodynamics | 2012 | No 4 December | 109-121 | DOI: 10.2478/v10173-012-0030-z
Keywords Free convection Thermal stratification Non-Newtonian Variable viscosity Porous medium
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Abstract

The aim of this paper is to investigate the effect of thermal stratification together with variable viscosity on free convection flow of non- Newtonian fluids along a nonisothermal semi infinite vertical plate embedded in a saturated porous medium. The governing equations of continuity, momentum and energy are transformed into nonlinear ordinary differential equations using similarity transformations and then solved by using the Runge-Kutta-Gill method along with shooting technique. Governing parameters for the problem under study are the variable viscosity, thermal stratification parameter, non-Newtonian parameter and the power-law index parameter.The velocity and temperature distributions are presented and discussed. The Nusselt number is also derived and discussed numerically.
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Authors and Affiliations

M.B.K. Moorthy
K. Senthilvadivu

Effect of lubricant compressibility and variable viscosity on the performance of three-lobe journal bearing

Mushrek A. Mahdi Basim Ajeel Abbas
Archive of Mechanical Engineering | 2022 | vol. 69 | No 2 | 203-219 | DOI: 10.24425/ame.2022.140412
Keywords hydrodynamic lubrication journal bearings compressibility effect variable viscosity
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Abstract

Different configurations of journal bearings have been extensively used in turbomachinery and power generating equipment. Three-lobe bearing is used due to its lower film temperature and stable operation. In this study, static performance of such a bearing has been investigated at different eccentricity ratios considering lubricant compressibility and variable viscosity. The effect of variable viscosity was considered by taking the viscosity as a function of the oil film thickness while Dowson model is used to consider the effect of lubricant compressibility. The effect of such parameters was considered to compute the oil film pressure, load-carrying capacity, attitude angle and oil side leakage for a bearing working at (ε from 0.6 to 0.8) and (viscosity coefficient from 0 to 1). The mathematical model as well as the computer program prepared to solve the governing equations were validated by comparing the pressure distribution obtained in the present work with that obtained by EL-Said et al. A good agreement between the results has been observed with maximum deviation of 3%. The obtained results indicate a decrease in oil film pressure and load-carrying capacity with the higher values of viscosity coefficient while the oil compressibility has a little effect on such parameters.
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Bibliography

[1] R. Sinhasan, M. Malik, and M. Chandra. A comparative study of some three-lobe bearing configurations. Wear, 72(3):277–286, 1981. doi: 10.1016/0043-1648(81)90254-4.
[2] K. Prabhakaran Nair, R. Sinhasan, and D.V. Singh. A study of elasto-hydrodynamic effects in a three-lobe journal bearing. Tribology International, 20(3):125–132, 1987. doi: 10.1016/0301-679X(87)90042-9.
[3] K.C. Goyal and R Sinhasan. Elastohydrodynamic studies of three-lobe journal bearings with non-Newtonian lubricants. Proceedings of the Institution of Mechanical Engineers, Part C: Mechanical Engineering Science, 205(6):379–388, 1991, doi: 10.1243/PIME_PROC_ 1991_205_135_02.
[4] N.P. Mehat and S.S. Rattan. Performance of three-lobe pressure-dam bearings. Tribology International, 26(6):435–442, 1993. doi: 10.1016/0301-679X(93)90084-E.
[5] M. Malik, R. Sinhasan, and M. Chandra. Design data for three-lobe bearings. ASLE Transactions, 24(3):345–353, 2008, doi: 10.1080/05698198108983031.
[6] N.K. Batra, Gian Bhushan, and N.P. Mehta. Effect of L/D ratio on the performance of an inverted three-lobe pressure dam bearing. Journal of Engineering and Technology, 1(2):94–99, 2011.
[7] L. Roy and S.K. Kakoty. Groove location for optimum performance of three- and four-lobe bearings using genetic algorithm. Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology, 229(1):47–53, 2015. doi: 10.1177/1350650114541253.
[8] A. Chasalevris. Analytical evaluation of the static and dynamic characteristics of three-lobe journal bearings with finite length. Journal of Tribology, 137(4):041701, 2015. doi: 10.1115/1.4030023.
[9] A.K.H. EL-Said, B.M. EL-Souhily, W.A. Crosby, and H.A. EL-Gamal. The performance and stability of three-lobe journal bearing textured with micro protrusions. Alexandria Engineering Journal, 56(4):423–432, 2017. doi: 10.1016/j.aej.2017.08.003.
[10] D.Y. Dhande, D.W. Pande, and G.H. Lanjewar. Numerical analysis of three lobe hydrodynamic journal bearing using CFD–FSI technique based on response surface evaluation. Journal of the Brazilian Society of Mechanical Sciences and Engineering, 40(393):1–16, 2018. doi: 10.1007/s40430-018-1311-5.
[11] TVVLN Rao, A.M.A. Rani, Norani M. Mohamed, H.H. Ya, M. Awang, and F.M. Hashim. Static and stability analysis of partiaslip texture multi-lobe journal bearings. Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology, 234(4):567–587, 2019, doi: 10.1177/1350650119882834.
[12] P. Sinha, C. Singh, and K.R. Prasad. Effect of viscosity variation due to lubricant additives in journal bearings. Wear, 66(2):175–188, 1981. doi: 10.1016/0043-1648(81)90112-5.
[13] N.B. Naduvinamani and A.K. Kadadi. Effect of viscosity variation on the micropolar fluid squeeze film lubrication of a short journal bearing. Advances in Tribology, 2013:id743987, 2013. doi: 10.1155/2013/743987.
[14] J.R. Patel and G. Deheri. Viscosity variation effect on the magnetic fluid lubrication of a short bearing. Journal of the Serbian Society for Computational Mechanics, 13(2):56–66, 2019. doi: 10.24874/jsscm.2019.13.02.05.
[15] Q. Qu, H. Zhang, L. Zhou, and C. Wang. The analysis of the characteristics of infinitely short journal bearings modified by equivalent viscosity. 2010 International Conference on Measuring Technology and Mechatronics Automation, 754–757, 2010. doi: 10.1109/ICMTMA.2010.357.
[16] A. Siddangouda, T.V. Biradar, and N.B. Naduvinamani. Combined effects of surface roughness and viscosity variation due to additives on long journal bearing. Tribology – Materials, Surfaces & Interfaces, 7(1):21–35, 2013. doi: 10.1179/1751584X13Y.0000000024.
[17] L. Bertocchi, M. Giacopini, A. Strozzi, M.T. Fowell, and D. Dini. A mass-conserving complementarity formulation to study fluid film lubrication in the presence of cavitation for non-Newtonian and compressible fluids. Proceedings of the ASME 2012 11th Biennial Conference on Engineering Systems Design and Analysis, volume 4, pages 629–635, Nantes, France, July 2–4, 2012. doi: 10.1115/ESDA2012-82885.
[18] M. Besanjideh and S.A. Gandjalikhan Nassab. Effect of lubricant compressibility on hydrodynamic behavior of finite length journal bearings. running under heavy load conditions. Journal of Mechanics, 32(1):101–111, 2016. doi: 10.1017/jmech.2015.51.
[19] N. Tipei. Theory of Lubrication: with Applications to Liquid and Gas Film Lubrication. chapter 3, Stanford University Press, 1962.
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Authors and Affiliations

Mushrek A. Mahdi
1
ORCID: ORCID
Basim Ajeel Abbas
2
  1. University of Babylon, College of Engineering/Al-Musayab, Automobile Engineering Department, Babylon, Iraq
  2. University of Babylon, College of Engineering, Mechanical Engineering Department, Babylon, Iraq

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