A theoretical and experimental investigation of a gas-operated bearing damper for turbomachinery. Part 1: Theoretical model and predictions

Journal Article · Sun Oct 01 04:00:00 EDT 1995 · Journal of Engineering for Gas Turbines and Power

DOI:https://doi.org/10.1115/1.2815460· OSTI ID:137090

Sundararajan, P; Vance, J M ^[1]

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1. Texas A and M Univ., College Station, TX (United States)

This is the first (Part 1) of two papers describing recent results of the research program directed at developing a vibration damper suitable for high-temperature turbomachinery applications. It is expected that such dampers will replace squeeze-film dampers, which use oil as the working fluid and have limitations at higher temperatures. A novel gas-operated bearing damper has been evaluated analytically and experimentally for its damping characteristics. A theory based on the isentropic assumptions predicts the damper performance characteristics reasonably well. A maximum damping level of 2,311 N-m/s (13.2 lb-s/in.) at a frequency of 100 Hz was measured with a single actuator of the gas damper. Since many such actuators could be placed circumferentially around the squirrel cage, considerable damping levels can be realized. The study also shows that significantly higher damping levels can be achieved by modifying the current design. Part 1 describes the theoretical model that has been developed based on isentropic assumptions. This model is an improved version of the previous theory (Vance et al., 1991) and includes the supply groove effects, dynamic area changes of the inlet feeding holes, and the effects of flow choking on damper behavior. The governing equations are derived and theoretical predictions using these equations have been made for two hardware designs that were experimentally investigated (see Part 2 for experimental results).

• Sponsoring Organization: USDOE
• OSTI ID: 137090
• Journal Information: Journal of Engineering for Gas Turbines and Power, Journal Name: Journal of Engineering for Gas Turbines and Power Journal Issue: 4 Vol. 117; ISSN JETPEZ; ISSN 0742-4795
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
AIRCRAFT
DAMPING
GAS TURBINE ENGINES
MATHEMATICAL MODELS
MECHANICAL VIBRATIONS