ORCID Identifier(s)

0000-0002-2589-0711

Graduation Semester and Year

2022

Language

English

Document Type

Thesis

Degree Name

Master of Science in Mechanical Engineering

Department

Mechanical and Aerospace Engineering

First Advisor

Daejong Kim

Second Advisor

Seiichi Nomura

Abstract

It has been known for many decades that both rigid and foil thrust bearings are two options in the market for high-speed turbomachinery systems. Their advantages encompass the lower manufacturing cost, the lighter weight, and the flexibility in allowing “component misalignment and runout.” When the operating fluid is air, the classical lubrication theory works perfectly. Any additional terms of the inertia effect might be somehow less significant and sometimes negligible since the viscous forces will be dominant, but this may not be the case if the bearing operates in a harsh environment, such as a high-pressure environment. Nonetheless, this is a different scenario when dealing with water or denser gases lubricated bearings since the inertia forces have significance and effects as same as the viscous forces. Therefore, the classical lubrication theory, where the inertia forces are very small – Modified Reynolds number (Re) << 1 – should be rederived and modified to include those additional terms. As they play a major role in affecting the bearing performance by reducing its load capacity, they should be considered. This thesis shows the comparison of both solutions when inertial terms are considered and when they are not through the comparison of the local Reynold number, pressure, streamlines, deflections, and load capacity.

Keywords

Inertial effect, Centrifugal force, Centrifugal effect, Load capacity, Load capacity of thrust bearing, Thrust bearing, Thrust gas bearing, Load capacity of thrust gas bearing

Disciplines

Aerospace Engineering | Engineering | Mechanical Engineering

Comments

Degree granted by The University of Texas at Arlington

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