Stability analysis of electrorheological (ER) lubricant operated multilobe hydrodynamic journal bearing
Abstract
Purpose
An electrorheological (ER) fluid consists of dielectric particles blended in a nonconducting oil. ER lubricants are often considered smart lubricants. This paper aims to examine the steady state and dynamic response of multilobe journal bearings using an ER lubricant.
Design/methodology/approach
Reynold’s equation has been used to describe the lubricant flow in the journal-bearing clearance space. The Bingham model is used to characterize the nonlinear behavior of the lubricant. The solution of the Reynolds equation is obtained using the Newton–Raphson method, with gaseous cavitation in the fluid film numerically addressed by applying a mass-conserving algorithm. The effects of lobe geometry and the applied electric field are investigated on film pressure profile, fluid film thickness, direct stiffness and damping parameters. The equation of motion for journal center coordinates is solved using the fourth-order Runge–Kutta method, to predict journal center motion trajectories.
Findings
Using ER lubricant combined with two-lobe journal bearing significantly improved the minimum film thickness by 49.75%, the direct stiffness parameter by 132.18% and the damping parameter by 206.3%. However, the multilobe configuration was found to negatively impact the frictional powerloss of the bearing system. In the case of multilobe configurations of journal bearings using ER lubricant, linear motion journal trajectories are observed to be reduced and exhibit increased stability.
Originality/value
This study presents the effect of an ER lubricant and multilobe configuration on the rotor-dynamic performance and stability analysis of hydrodynamic journal bearings.
Peer review
The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-06-2024-0201/
Keywords
Acknowledgements
This research did not receive any specific funding from public, commercial or nonprofit sector.
Ethical compliance: All procedures conducted in studies involving human participants adhered to the ethical standards set by the institutional and/or national research committee, as well as the principles outlined in the 1964 Helsinki Declaration and its subsequent amendments, or equivalent ethical standards.
Citation
Narwat, K., Kumar, V., Singh, S.J. and Kumar, A. (2024), "Stability analysis of electrorheological (ER) lubricant operated multilobe hydrodynamic journal bearing", Industrial Lubrication and Tribology, Vol. ahead-of-print No. ahead-of-print. https://doi.org/10.1108/ILT-06-2024-0201
Publisher
:Emerald Publishing Limited
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