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Title: Integration of magnetic bearings in the design of advanced gas turbine engines

Abstract

Active magnetic bearings provide revolutionary advantages for gas turbine engine rotor support. These advantages include tremendously improved vibration and stability characteristics, reduced power loss, improved reliability, fault tolerance, and greatly extended bearing service life. The marriage of these advantages with innovative structural network design and advanced materials utilization will permit major increases in thrust-to-weight performance and structural efficiency for future gas turbine engines. However, obtaining the maximum payoff requires two key ingredients. The first is the use of modern magnetic bearing technologies such as innovative digital control techniques, high-density power electronics, high-density magnetic actuators, fault-tolerant system architecture, and electronic (sensorless) position estimation. This paper describes these technologies and the test hardware currently in place for verifying the performance of advanced magnetic actuators, power electronics, and digital controls. The second key ingredient is to go beyond the simple replacement of rolling element bearings with magnetic bearings by incorporating magnetic bearings as an integral part of the overall engine design. This is analogous to the proper approach to designing with composites, whereby the designer tailors the geometry and load-carrying function of the structural system or component for the composite instead of simply substituting composites in a design originally intended for metal material.more » This paper describes methodologies for the design integration of magnetic bearings in gas turbine engines.« less

Authors:
;  [1]; ;  [2]
  1. General Electric Co., Cincinnati, OH (United States). General Electric Aircraft Engines
  2. General Electric Co., Schenectady, NY (United States). Corporate Research and Development
Publication Date:
Sponsoring Org.:
USDOE
OSTI Identifier:
169982
Report Number(s):
CONF-940626-
Journal ID: JETPEZ; ISSN 0742-4795; TRN: IM9605%%1
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Engineering for Gas Turbines and Power; Journal Volume: 117; Journal Issue: 4; Conference: 39. international gas turbine and aeroengine congress and exposition, The Hague (Netherlands), 13-16 Jun 1994; Other Information: PBD: Oct 1995
Country of Publication:
United States
Language:
English
Subject:
20 FOSSIL-FUELED POWER PLANTS; 32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION; GAS TURBINE ENGINES; MAGNETIC BEARINGS; DESIGN; COMPUTERIZED CONTROL SYSTEMS; MECHANICAL STRUCTURES; RESPONSE FUNCTIONS

Citation Formats

Storace, A.F., Sood, D., Lyons, J.P., and Preston, M.A. Integration of magnetic bearings in the design of advanced gas turbine engines. United States: N. p., 1995. Web. doi:10.1115/1.2815450.
Storace, A.F., Sood, D., Lyons, J.P., & Preston, M.A. Integration of magnetic bearings in the design of advanced gas turbine engines. United States. doi:10.1115/1.2815450.
Storace, A.F., Sood, D., Lyons, J.P., and Preston, M.A. Sun . "Integration of magnetic bearings in the design of advanced gas turbine engines". United States. doi:10.1115/1.2815450.
@article{osti_169982,
title = {Integration of magnetic bearings in the design of advanced gas turbine engines},
author = {Storace, A.F. and Sood, D. and Lyons, J.P. and Preston, M.A.},
abstractNote = {Active magnetic bearings provide revolutionary advantages for gas turbine engine rotor support. These advantages include tremendously improved vibration and stability characteristics, reduced power loss, improved reliability, fault tolerance, and greatly extended bearing service life. The marriage of these advantages with innovative structural network design and advanced materials utilization will permit major increases in thrust-to-weight performance and structural efficiency for future gas turbine engines. However, obtaining the maximum payoff requires two key ingredients. The first is the use of modern magnetic bearing technologies such as innovative digital control techniques, high-density power electronics, high-density magnetic actuators, fault-tolerant system architecture, and electronic (sensorless) position estimation. This paper describes these technologies and the test hardware currently in place for verifying the performance of advanced magnetic actuators, power electronics, and digital controls. The second key ingredient is to go beyond the simple replacement of rolling element bearings with magnetic bearings by incorporating magnetic bearings as an integral part of the overall engine design. This is analogous to the proper approach to designing with composites, whereby the designer tailors the geometry and load-carrying function of the structural system or component for the composite instead of simply substituting composites in a design originally intended for metal material. This paper describes methodologies for the design integration of magnetic bearings in gas turbine engines.},
doi = {10.1115/1.2815450},
journal = {Journal of Engineering for Gas Turbines and Power},
number = 4,
volume = 117,
place = {United States},
year = {Sun Oct 01 00:00:00 EDT 1995},
month = {Sun Oct 01 00:00:00 EDT 1995}
}
  • Three decades of research by U.S. industry and government laboratories have produced a vast array of data related to the use of ceramic rolling element bearings and bearing components for aircraft gas turbine engines. Materials such as alumina, silicon carbide, titanium carbide, silicon nitride, and a crystallized glass ceramic have been investigated. Rolling element endurance tests and analysis of full complement bearings have been performed. Materials and bearing design methods have continuously improved over the years. This paper reviews a wide range of data and analyses the emphasis on how early NASA contributions as well as more recent data canmore » enable the engineer or metallurgist to determine just where ceramic bearings are most applicable for gas turbines.« less
  • Three decades of research by U.S. industry and government laboratories have produced a vast body of data related to the use of ceramic rolling element bearings and bearing components for aircraft gas turbine engines. Materials such as alumina, silicon carbide, titanium carbide, silicon nitride, and a crystallized glass ceramic have been investigated. Rolling-element endurance tests and analysis of full-complement bearings have been performed. Materials and bearing design methods have continuously improved over the years. This paper reviews a wide range of data and analyses with emphasis on how early NASA contributions as well as more recent data can enable themore » engineer or metallurgist to determine just where ceramic bearings are most applicable for gas turbines. 46 refs.« less
  • Norton/TRW Ceramics (NTC) is developing ceramic components as part of the DOE-sponsored Advanced Turbine Technology Applications Project (ATTAP). NTC's work is directed at developing manufacturing technologies for rotors, stators, vane-seat platforms, and scrolls. The first three components are being produced from a HIPed Si[sub 3]N[sub 4], designated NT154. Scrolls were prepared from a series of siliconized silicon-carbide (Si-SiC) materials designated NT235 and NT230. Efforts during the first three years of this five-year program are reported. Developmental work has been conducted on all aspects of the fabrication process using Taguchi experimental design techniques. Appropriate materials and processing conditions were selected formore » power beneficiation, densification, and heat-treatment operations. Component forming has been conducted using thermal-plastic-based injection molding (IM), pressure slip-casting (PSC), and Quick-Set[sup TM] injection molding. An assessment of material properties for various components from each material and process were made. For NT154, characteristic room-temperature strengths and Weibull Moduli were found to range between [approx]920 MPa to [approx]1 GPa and [approx]10 to [approx]19, respectively. Process-induced inclusions proved to be the dominant strength-limiting defect regardless of the chosen forming method. Correction of the lower observed values is being addressed through equipment changes and upgrades. For the NT230 and NT235 Si-SiC, characteristic room-temperature strengths and Weibull Moduli ranged from [approx]240 to [approx]420 MPa, and 8 to 10, respectively. At 1370C, strength values for both the HIPed Si[sub 3]N[sub 4] and the Si-SiC materials ranged from [approx]480 MPa to [approx]690 MPa. The durability of these materials as engine components is currently being evaluated.« less
  • The wave rotor is a promising means of pressure-gain for gas turbine engines. This paper examines novel wave rotor topping cycles that incorporate low-NO{sub x} combustion strategies. This approach combines two-stage rich-quench-lean (RQL) combustion with intermediate expansion in the wave rotor to extract energy and reduce the peak stoichiometric temperature substantially. The thermodynamic cycle is a type of reheat cycle, with the rich-zone air undergoing a high-pressure stage. Rich-stage combustion could occur external to or within the wave rotor. An approximate analytical design method and CFD/combustion codes are used to develop and simulate wave rotor flow cycles. Engine cycles designedmore » with a bypass turbine and external combustion demonstrate a performance enhancement equivalent to a 200--400 R (110--220 K) increase in turbine inlet temperature. The stoichiometric combustion temperature is reduced by 300--450 R (170--250 K) relative to an equivalent simple cycle, implying substantially reduced NO{sub x} formation.« less
  • Garrett Auxiliary Power Division of Allied-Signal Aerospace Company is developing methods to design ceramic turbine components with improved impact resistance. In an ongoing research effort under the DOE/NASA-funded Advanced Turbine Technology Applications Project (ATTAP), two different modes of impact damage have been identified and characterized: local damage and structural damage. Local impact damage to Si[sub 3]N[sub 4] impacted by spherical projectiles usually takes the form of ring and/or radial cracks in the vicinity of the impact point. Baseline data from Si[sub 3]N[sub 4] test bars impacted by 1.588-mm (0.0625-in.) diameter NC-132 projectiles indicates the critical velocity at which the probabilitymore » of detecting surface cracks is 50 percent equaled 130 m/s (426 ft/sec). A microphysics-based model that assumes damage to be in the form of microcracks has been developed to predict local impact damage. Local stress and strain determine microcrack nucleation and propagation, which in turn alter local stress and strain through modulus degradation. Material damage is quantified by a damage parameter related to the volume fraction of microcracks. The entire computation has been incorporated into the EPIC computer code. Model capability is being demonstrated by simulating instrumented plate impact and particle impact tests. Structural impact damage usually occurs in the form of fast fracture caused by bending stresses that exceed the material strength. The EPIC code has been successfully used to predict radial and axial blade failures from impacts by various size particles. This method is also being used in conjunction with Taguchi experimental methods to investigate the effects of design parameters on turbine blade impact resistance. It has been shown that significant improvement in impact resistance can be achieved by using the configuration recommended by Taguchi methods.« less