Effect of roughness on journal bearing performance with non-newtonian fluids / K. Jagannath

The present study investigates the effect of surface roughness properties on the steady-state and dynamic characteristics of hydro dynamic journal bearing using non-Newtonian lubricants obeying power-law model. An analytical expression for average film thickness is obtained and introduced in the mo...

Full description

Bibliographic Details
Main Author: Jagannath, K.
Format: Article
Language:English
Published: UiTM Press 2010
Subjects:
Online Access:https://ir.uitm.edu.my/id/eprint/13734/1/AJ_K%20JAGANNATH%20JME%2010.pdf
_version_ 1796899880672690176
author Jagannath, K.
author_facet Jagannath, K.
author_sort Jagannath, K.
collection UITM
description The present study investigates the effect of surface roughness properties on the steady-state and dynamic characteristics of hydro dynamic journal bearing using non-Newtonian lubricants obeying power-law model. An analytical expression for average film thickness is obtained and introduced in the modified Reynolds equation. The resulting differential equation is then solved by the finite difference method with a successive over-relaxation scheme. The modified Reynolds equation with rough surfaces having Gaussian distribution has been solved using the non-linear transient approach to determine the stability parameters considering longitudinal, transverse and isotropic roughness patterns. The equation of motion is then solved by the fourth-order Runge- Kutta method. The results are compared with established results for smooth bearings. It is found from the detailed analysis that roughness parameter considerably influences stability of journal bearings. Stability is highest when the bearing is rough than journal. Surface pattern orientation of bearings has an important role in determining the stable running of a bearing. Improvement in stability not only depends on whether the surfaces have isotropically, longitudinally, or transversely oriented surface but also on the variation in the roughness between journal and bearing. Transversely oriented surface with rough bearing gives higher stability. Lower L/D ratios (short bearing) gives better stability characteristics. Non-Newtonian effects cause the maximum film pressure to increase. It is observed from the pressure distribution that for different values of flow behavior index, non-Newtonian lubricants show flatter pressure distribution which is advantageous for bearings subjected to oscillatory loads.
first_indexed 2024-03-06T01:27:28Z
format Article
id oai:ir.uitm.edu.my:13734
institution Universiti Teknologi MARA
language English
last_indexed 2024-03-06T01:27:28Z
publishDate 2010
publisher UiTM Press
record_format dspace
spelling oai:ir.uitm.edu.my:137342016-07-25T03:44:39Z https://ir.uitm.edu.my/id/eprint/13734/ Effect of roughness on journal bearing performance with non-newtonian fluids / K. Jagannath jmeche Jagannath, K. Surface effects and tests The present study investigates the effect of surface roughness properties on the steady-state and dynamic characteristics of hydro dynamic journal bearing using non-Newtonian lubricants obeying power-law model. An analytical expression for average film thickness is obtained and introduced in the modified Reynolds equation. The resulting differential equation is then solved by the finite difference method with a successive over-relaxation scheme. The modified Reynolds equation with rough surfaces having Gaussian distribution has been solved using the non-linear transient approach to determine the stability parameters considering longitudinal, transverse and isotropic roughness patterns. The equation of motion is then solved by the fourth-order Runge- Kutta method. The results are compared with established results for smooth bearings. It is found from the detailed analysis that roughness parameter considerably influences stability of journal bearings. Stability is highest when the bearing is rough than journal. Surface pattern orientation of bearings has an important role in determining the stable running of a bearing. Improvement in stability not only depends on whether the surfaces have isotropically, longitudinally, or transversely oriented surface but also on the variation in the roughness between journal and bearing. Transversely oriented surface with rough bearing gives higher stability. Lower L/D ratios (short bearing) gives better stability characteristics. Non-Newtonian effects cause the maximum film pressure to increase. It is observed from the pressure distribution that for different values of flow behavior index, non-Newtonian lubricants show flatter pressure distribution which is advantageous for bearings subjected to oscillatory loads. UiTM Press 2010 Article PeerReviewed text en https://ir.uitm.edu.my/id/eprint/13734/1/AJ_K%20JAGANNATH%20JME%2010.pdf Effect of roughness on journal bearing performance with non-newtonian fluids / K. Jagannath. (2010) Journal of Mechanical Engineering (JMechE) <https://ir.uitm.edu.my/view/publication/Journal_of_Mechanical_Engineering_=28JMechE=29/>, 7 (1). pp. 1-13. ISSN 1823-5514 ; 2550-164X https://jmeche.uitm.edu.my/
spellingShingle Surface effects and tests
Jagannath, K.
Effect of roughness on journal bearing performance with non-newtonian fluids / K. Jagannath
title Effect of roughness on journal bearing performance with non-newtonian fluids / K. Jagannath
title_full Effect of roughness on journal bearing performance with non-newtonian fluids / K. Jagannath
title_fullStr Effect of roughness on journal bearing performance with non-newtonian fluids / K. Jagannath
title_full_unstemmed Effect of roughness on journal bearing performance with non-newtonian fluids / K. Jagannath
title_short Effect of roughness on journal bearing performance with non-newtonian fluids / K. Jagannath
title_sort effect of roughness on journal bearing performance with non newtonian fluids k jagannath
topic Surface effects and tests
url https://ir.uitm.edu.my/id/eprint/13734/1/AJ_K%20JAGANNATH%20JME%2010.pdf
work_keys_str_mv AT jagannathk effectofroughnessonjournalbearingperformancewithnonnewtonianfluidskjagannath