Linear stability analysis of finite length journal bearings in laminar and turbulent regimes
Author | Miraskari, Mohammad |
Author | Hemmati, Farzad |
Author | Alqaradawi, M. Y. |
Author | Gadala, Mohamed S. |
Available date | 2020-11-04T08:52:36Z |
Publication Date | 2017 |
Publication Name | Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology |
Resource | Scopus |
ISSN | 13506501 |
Abstract | Dynamic coefficients of a finite length journal bearing are numerically calculated under laminar and turbulent regimes based on Ng-Pan-Elrod and Constantinescu models. Linear stability charts of a flexible rotor supported on laminar and turbulent journal bearings are found by calculating the threshold speed of instability associated to the start of instable oil whirl phenomenon. Local journal trajectories of the rotor-bearing system were found at different operating conditions solely based on the calculated dynamic coefficients in laminar and turbulent flow. Results show no difference between laminar and turbulent models at low loading while significant change of the size of the stable region was observed by increasing the Reynolds number in turbulent models. Stable margins based on the laminar flow at relatively low Sommerfeld numbers S ? 0. 05 were shown to fall inside the unstable region and hence rendering the laminar stability curves obsolete at high Reynolds numbers. Ng-Pan turbulent model was found to be generally more conservative and hence is recommended for rotor-bearing design. 1 Institution of Mechanical Engineers. |
Sponsor | The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: The authors would like to thank the Qatar National Research Fund (QNRF) for partially funding this project. |
Language | en |
Publisher | SAGE Publications Ltd |
Subject | dynamic coefficients Finite length journal bearing Ng-Pan-Elrod and Constantinescu turbulent models oil whirl stability threshold speed of instability |
Type | Article |
Pagination | 1254-1267 |
Issue Number | 10 |
Volume Number | 231 |
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Mechanical & Industrial Engineering [1343 items ]