Open Access
Subscription Access
Open Access
Subscription Access
Analyzing Short Porous Hydrodynamic Journal Bearing Numerically Considering Micropolar Lubrication and Isotropic Roughness
Subscribe/Renew Journal
In present days of high speed machines and machinery, the aim to reduce the energy loses becomes a major aspect of research for economic reasons and long-term reliability. It is known that an industrial nation can save about 1% of gross national product by better tribological exercises. Many modern machines use porous bearings for its ability to act as a lubricant reservoir. The lubricant used in the open adverse operating situations gets contaminated with worn-out particles and dust, and can be better studied by micropolar lubrication theory. Moreover, machined surfaces always have some degree of roughness which adds to the loss of energy. The present work aims at clubbing the effect of roughness in hydrodynamic lubrication using micropolar fluid with a thin porous bush assuming the velocity slip of lubricant film at the porous bush and fluid film junction. The governing equation for fluid pressure in the porous matrix and hydrodynamic film zone are developed following Darcy’s equation and hydrodynamic micropolar lubrication theory, considering Christensen’s stochastic model of roughness. The bearing is approximated as a short one. Modified Reynold’s equation is numerically solved to compute fluid film pressure in steady-state condition. Friction parameters and non-dimensional load capacity in terms of roughness parameters and porous bearing characteristics are presented in case of Newtonian and micropolar fluids.
Keywords
Micropolar Lubricant, Porous Journal Bearing, Stochastic Roughness.
User
Subscription
Login to verify subscription
Font Size
Information
- Allmaier, H., Priestner, C., Six, C., Priebsch, H. H., Forstne, C. and NovotnyFarkas F., Predicting friction reliably and accurately in journal bearings; a systematic validation of simulation results with experimental measurements, Tribology International, Vol.44, pp. 1151—1160, 2011.
- Jost, P. H. and Schofield, J., Energy saving through tribology: a techno economic study, Proc. Ins. Mech. Engrs., A Technical Report, Vol. 195, pp. 151-173, 1981.
- Jost, P. H., Tribology-origin and failure, Wear, A Technical Report, Vol. 136, pp. 1 17, 1990.
- Eringen, A. C., Theory of micropolar fluids, J. Math. Mech., Vol.16, No.1, 1966, PP.1-18.
- Khonsari, M. M. and Brewe, D. E., On the performance of finite journal bearings lubricated with Micropolar fluids, STLE, Tribology Trans., Vol.32, No.2, pp.155160, 1989.
- Christensen, H., Stochastic model for hydrodynamic lubrication of rough surfaces, Proce. Ins. Mech. Engrs., Vol. 184, No.55, pp. 1013-1025, 1969.
- Christensen, H. and Tonder, K., The hydrodynamic lubrication of rough bearing surfaces of finite width, Trans. ASME, Vol. 7, No. 17, pp. 324-329, 1971.
- Christensen, H. and Tonder, K., The hydrodynamic lubrication of rough journal bearings, Trans. ASME, J. of Lubr. Tech., Series F., Vol.34, pp.166-70, 1973.
- Prakash, J., Christensen, H. and Tonder, K., Micropolarity-roughness interaction in hydrodynamic lubrication, Trans. ASME, Vol. 102, pp.368-372, 1980.
- Patir, N. and Cheng, H. S., An average flow model for determining effects of three-dimensional roughness on partial hydrodynamic lubrication, Trans. ASME J. Lubr. Technol., Vol. 100, No. 1, pp. 12-17, 1978.
- Majumdar, B. C. and Hamrock, B. J., Surface roughness effect on finite oil journal bearings, NASA Technical Memo no. 82639, NASA, Washington, DC, 1981.
- Majumdar, B. C. and Ghosh, M. K., Stability of a rigid rotor supported on rough oil journal bearings, Trans. ASME, Journal of Tribology, Vol. 112, pp,73-77, 1990.
- Rasheed, E. H., Effects of surface waviness on the hydrodynamic lubrication of a plain cylindrical sliding element bearing, Wear, Vol. 223, pp.1-6, 1998.
- Murti, P. R. K., Hydrodynamic lubrication of finite porous bearings, Wear, Vol. 19, No. 1, pp. 113-115, 1972.
- Ting, L.L., Engagement behavior of lubricated porous annular disks part-l, Squeeze film phase- Surface roughness and elastic deformation effects, Wear, Vol. 34, pp-159-172, 1975.
- Prakash, J., Tiwari, K., Lubrication of a porous bearing with surface corrugations, ASME J. Lubr. Technol., Vol. 104, No. 1, pp. 127-134, 1982.
- Prakash, J. and Gururajan, K., Effect of velocity slip in an infinitely long rough porous journal bearing, STLE Tribol. Trans., Vol. 42, pp. 661-667, 1999.
- Gururajan, K. and Prakash, J., Effect of velocity slip in a narrow rough porous journal bearing, Proc. Instn Mech. Engrs, Part J: J. Engineering Tribology, Vol. 217, pp. 59-70, 2003.
- Beavers, G. S. and Joseph, D. D., Boundary conditions at a naturally permeable wall, J. Fluid Mech., Vol. 30, No 1, pp. 191-207, 1967.
- Beavers, G. S., Sparrow, E. M. and Masha, B. A., Boundary condition at a porous surface which bounds a fluids flow, AICHE Journal, Vol. 20 No 3, pp. 596-97, 1974.
- Murti, P. R. K., Effect of slip-flow in narrow porous bearings with arbitrary wall thickness, J. Appl. Mech., Vol. 42, No 2, pp. 305-310, 1972.
- Prakash, J. and Vij, S. K., Analysis of narrow porous bearings using BeaversJoseph criterion of velocity slip, J. Appl. Mech., Vol. 96, pp. 346-353, 1974.
- Chattapadhyay, A. K., Mazumder, B. C. and Rao, N. S., Static and dynamic characteristics of finite oil journal bearings considering the tangential velocity slip, J. Lub. Technol. Trans ASME, Vol. 98, 76-Lub-E, pp. 412-417, 1985.
- Singh, C. and Sinha, P., The three-dimensional Reynolds equation for micropolar fluid lubricated bearings, Wear, Vol.76, No. 2, pp. 199-209, 1982.
- Huang, T. W., Weng, C. I. and Chen, C. K., Analysis of finite width journal bearings with micropolar fluids, Wear, Vol. 123, No. 1, pp. 1-12, 1988.
- Prakash, J. and Sinha, P., Lubrication theory of micropolar fluids and its application to a journal bearing, Int. J. Engg. Sci., Vol. 13, No. 3, pp. 217-232, 1975.
- Huang, T. W. and Weag, C. I., Dynamic characteristics of finite width journal bearings with micropolar fluids, Wear, Vol. 141, No. 1, pp. 23-33, 1990.
- Das, S., Guha, S. K. and Chattapadhyay, A. K., Linear stability analysis of hydrodynamic journal bearings under micropolar lubrication, Tribol. Int., Vol. 38, No. 5, pp. 500-507, 2005.
- Naduvimani, N. B. and Marali, G. B., Dynamic Reynolds equation for micropolar fluid lubrication of porous slider bearings, J. Marine Sci. and Technol., Vol. 16, No. 3, pp. 182-190, 2008.
- Siddangouda, A., Biradar, T. V. and Naduvinamani, N. B., Combined effects of surface roughness and viscosity variation due to additives on long journal bearing, Tribology- Materials, Surfaces and Interfaces, Vol.7, No.1, pp.21-35, 2013.
- Naduvinamani, N. B., Siddangouda, A., Biradar, N. S. and Kadadi, K. A., Combined effects of viscosity variation and surface roughness on the squeeze film lubrication of journal bearings with micropolar fluids, Tribology Online, Vol.9, No.4, pp. 175-183, 2014.
- Kumar, G., Jha K. S., Baidya, U., Das, S. and Das, S., Effect of surface roughness on the pressure generation in a finite rough hydrodynamic journal jearing under micropolar lubrication in steady-state, Reason- A Technical Journal, Vol. 15. pp.39-53, 2016.
- Baidya, U., Das, S. and Das, S., Porous hydrodynamic journal bearing analysis using micropolar fluid in steady-state condition, Tribology Online, Vol. 14, No.2, pp.-24-31, 2019.
- Cheng, I. and Weng, C. R. C., Linear stability of short journal bearings with consideration of flow rheology and surface roughness, Tribology International, Vol.34, No.1, pp.507-516, 2001.
Abstract Views: 464
PDF Views: 2