Accession Number:

ADA247566

Title:

Frequency Effects on the Stability of a Journal Bearing for Periodic Loading

Descriptive Note:

Technical memorandum

Corporate Author:

NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH LEWIS RESEARCH CENTER

Personal Author(s):

• Vijayaraghavan, D.
• Brewe, D. E.

Report Date:

1991-01-01

Pagination or Media Count:

21.0

Abstract:

In this paper, stability of a journal bearing is numerically predicted when unidirectional periodic external load is applied. The analysis is performed using a cavitation algorithm, which mimics the JFO theory by accounting for the mass balance through the complete bearing. Hence, the history of the film is taken into consideration. The loading pattern is taken to be sinusoidal and the frequency of the load cycle is varied. The results are compared with the predictions using Reynolds boundary conditions for both film rupture and reformation. With such comparisons, the need for accurately predicting the cavitation regions for complex loading patterns is clearly demonstrated. For a particular frequency of loading, the effects of mass, amplitude of load variation and frequency of journal speed are also investigated. The journal trajectories, transient variations in fluid film forces, net surface velocity and minimum film thickness and pressure profiles are also presented. Journal bearing, Dynamic loading, Stability, Frequency effects, Periodic loading, Nonlinear motion, Cavitation.

Descriptors:

• *LOADS(FORCES)
• *JOURNAL BEARINGS
• VELOCITY
• ALGORITHMS
• FREQUENCY
• TRANSIENTS
• THICKNESS
• THEORY
• MOTION
• CYCLES
• PATTERNS
• BALANCE
• PRESSURE
• HISTORY
• PROFILES
• BOUNDARIES
• SURFACES
• VARIATIONS
• REGIONS
• CAVITATION
• UNIDIRECTIONAL
• PAPER
• TRAJECTORIES
• AMPLITUDE
• BEARINGS
• EXTERNAL
• FLUIDS
• RUPTURE
• FILMS
• STABILITY
• ACCOUNTING
• PREDICTIONS
• DYNAMICS
• MASS

Subject Categories:

• Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE