Fail Safe, High Temperature Magnetic Bearing for High Efficiency Gas Turbine Engine Applications

2001 ◽  
Author(s):  
Alan Palazzolo ◽  
Gerald T. Montague ◽  
Yeonkyu Kim ◽  
Andrew Kenny ◽  
Randall Tucker ◽  
...  
Keyword(s):  
High Temperature ◽  
Test Performance ◽  
High Speed ◽  
High Efficiency ◽  
Magnetic Bearing ◽  
Test Results ◽  
Turbine Engine ◽  
Significant Extension ◽  
Actuator Control ◽  
Fail Safe

This paper contributes to the magnetic bearing literature in two distinct areas: high temperature and redundant actuation. Design considerations test results are given for the first published combined 538°C (1000°F)-high speed rotating test performance of a magnetic bearing. Secondly, a significant extension of the flux isolation based, redundant actuator control algorithm is proposed to eliminate the prior deficiency of changing position stiffness after failure.

scholarly journals Fail Safe, High Temperature Magnetic Bearings

2002 ◽  
Author(s):  
Thomas Minihan ◽  
Alan Palazzolo ◽  
Yeonkyu Kim ◽  
Shuliang Lei ◽  
Andrew Kenny ◽  
...  
Keyword(s):  
High Temperature ◽  
Test Performance ◽  
High Speed ◽  
Control Algorithm ◽  
Magnetic Bearing ◽  
The Novel ◽  
Test Results ◽  
Significant Extension ◽  
Actuator Control ◽  
Fail Safe

This paper contributes to the magnetic bearing literature in two distinct areas: high temperature and redundant actuation. Design considerations and test results are given for the first published combined 538°C (1000°F)-high speed rotating test performance of a magnetic bearing. Secondly, a significant extension of the flux isolation based, redundant actuator control algorithm is proposed to eliminate the prior deficiency of changing position stiffness after failure. The benefit of the novel extension was not experimentally demonstrated due to a high active stiffness requirement. In addition, test results are given for actuator failure tests at 399°C (750°F), 12,500rpm. Finally, simulation results are presented confirming the experimental data and validating the redundant control algorithm.

scholarly journals Leakage and Power Loss Test Results for Competing Turbine Engine Seals

2004 ◽  
Author(s):  
Margaret P. Proctor ◽  
Irebert R. Delgado
Keyword(s):  
High Temperature ◽  
Power Loss ◽  
High Speed ◽  
Operating Conditions ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Test Results ◽  
Test Rig ◽  
Labyrinth Seals ◽  
Turbine Engine

Advanced brush and finger seal technologies offer reduced leakage rates over conventional labyrinth seals used in gas turbine engines. To address engine manufactures’ concerns about the heat generation and power loss from these contacting seals, brush, finger, and labyrinth seals were tested in the NASA High Speed, High Temperature Turbine Seal Test Rig. Leakage and power loss test results are compared for these competing seals for operating conditions up to 922 K (1200 °F) inlet air temperature, 517 KPa (75 psid) across the seal, and surface velocities up to 366 m/s (1200 ft/s).

Coatings for High Temperature Foil Bearings

2007 ◽  
Author(s):  
Hooshang Heshmat ◽  
Said Jahanmir ◽  
James F. Walton
Keyword(s):  
High Temperature ◽  
High Speed ◽  
Magnetic Bearing ◽  
Magnetic Bearings ◽  
Turbine Engine ◽  
Foil Bearings ◽  
Limited Life ◽  
Wear Life ◽  
Tribological Coatings ◽  
Rolling Element

High operating speeds and temperatures required for advanced turbomachinery necessitate the development of bearings capable of continuous operation between 3 to 4 million DN at temperatures up to 820°C. Non-contact oil-free bearings such as compliant foil bearings, active magnetic bearings and hybrid foil and magnetic bearings are alternate solutions to the current liquid-lubricated hydrodynamic and rolling element bearings, which have limited life under these extreme conditions. A critical component in these oil-free bearings is the tribological coating system that must be used on the journal and the foil pads to ensure reliable operation during transient periods and start-stop cycles. The purpose of the present investigation was to assess the reliability of tribological coatings being implemented for a large (150 mm diameter) hybrid foil/magnetic bearing. In order to be suitable for use in large turbine engine type applications, the journal coating must accommodate the thermal and centrifugal growth experienced as well as providing the wear life and friction coefficient. Based upon the limitations identified in PS304, this coating is not yet suitable for demanding high temperature and high-speed applications. On the other hand an alternative nickel-chrome based coating applied to the foils versus a shaft with thin dense chrome or a nickel-chrome based coating a has shown excellent characteristics under conditions up to 820°C.

Performance of a Foil-Magnetic Hybrid Bearing

2000 ◽  
Author(s):  
Erik E. Swanson ◽  
Hooshang Heshmat ◽  
James Walton
Keyword(s):  
High Speed ◽  
Load Capacity ◽  
Magnetic Bearing ◽  
Experimental Program ◽  
Turbine Engine ◽  
Foil Bearing ◽  
Speed Performance ◽  
Hybrid Bearing ◽  
High Load Capacity ◽  
Bearing System

To meet the advanced bearing needs of modern turbomachinery, a hybrid foil-magnetic hybrid bearing system was designed, fabricated and tested in a test rig designed to simulate the rotor dynamics of a small gas turbine engine (31 kN to 53 kN thrust class). This oil-free bearing system combines the excellent low and zero-speed capabilities of the magnetic bearing with the high load capacity and high speed performance of the compliant foil bearing. An experimental program is described which documents the capabilities of the bearing system for sharing load during operation at up to 30,000 RPM and the foil bearing component’s ability to function as a back-up in case of magnetic bearing failure. At an operating speed of 22,000 RPM, loads exceeding 5300 N were carried by the system. This load sharing could be manipulated by an especially designed electronic control algorithm. In all tests, rotor excursions were small and stable. During deliberately staged magnetic bearing malfunctions, the foil bearing proved capable of supporting the rotor during continued operation at full load and speed, as well as allowing a safe rotor coast-down. The hybrid system tripled the load capacity of the magnetic bearing alone and can offer a significant reduction in total bearing weight compared to a comparable magnetic bearing.

scholarly journals High Temperature, Permanent Magnet Biased, Fault Tolerant, Homopolar Magnetic Bearing Development

2008 ◽  
Author(s):  
Alan Palazzolo ◽  
Randall Tucker ◽  
Andrew Kenny ◽  
Kyung-Dae Kang ◽  
Varun Ghandi ◽  
...  
Keyword(s):  
High Temperature ◽  
Design Methodology ◽  
Permanent Magnets ◽  
Fault Tolerant ◽  
State Of The Art ◽  
Magnetic Bearing ◽  
Test Results ◽  
Test Rig ◽  
Control Forces ◽  
Good Agreement

This paper summarizes the development of a magnetic bearing designed to operate at 1,000F. A novel feature of this high temperature magnetic bearing is its homopolar construction which incorporates state of the art high temperature, 1,000F, permanent magnets. A second feature is its fault tolerance capability which provides the desired control forces with over one-half of the coils failed. The construction and design methodology of the bearing is outlined and test results are shown. The agreement between a 3D finite element, magnetic field based prediction for force is shown to be in good agreement with predictions at room and high temperature. A 5 axis test rig will be complete soon to provide a means to test the magnetic bearings at high temperature and speed.

Foil Air/Gas Bearing Technology — An Overview

1997 ◽  
Author(s):  
Giri L. Agrawal
Keyword(s):  
High Temperature ◽  
Analytical Methods ◽  
High Speed ◽  
Test Results ◽  
Air Bearings ◽  
Mean Time Between Failure ◽  
Foil Bearing ◽  
Cryogenic Liquids ◽  
Gas Bearing ◽  
Mean Time

This paper summarizes the chronological progress of foil air bearings for turbomachinery during the last 25 years. Descriptions of various machines which are in production are provided. The foil bearing air cycle machine on the 747 aircraft has demonstrated an MTBF (mean time between failure) in excess of 100,000 hours. Many advantages of foil air bearings are noted. Various designs of foil air bearings presently in use and their relative merits are described. Analytical methods, their limitations, and their relationships with test results are noted. Descriptions of various machines built and tested in process fluids being gases, other than air, and cryogenic liquids are described. Conclusions are drawn that various high speed turbomachines including high temperature applications can be designed and developed using foil air bearings which will increase efficiency and reduce cost of these machines.

scholarly journals The Use Of Microturbines as an Energy Converter For Motor Transport

2019 ◽  
Vol 8 (10) ◽  
pp. 2700-2703
Keyword(s):  
Fuel Consumption ◽  
High Speed ◽  
Internal Combustion Engines ◽  
High Efficiency ◽  
Mechanical Energy ◽  
Electrical Energy ◽  
Motor Vehicles ◽  
Turbine Engine ◽  
Range Extender ◽  
Traction Motors

At this stage of the development of vehicles with a combined power plant, one of the areas of development is the study of the introduction of a low-power gas turbine engine, the so-called microturbine, as a converter of thermal energy into mechanical. This solution has numerous positive aspects related to its fuel consumption, small dimensions, high efficiency, as well as a number of performance indicators. In this case, the vehicle is also equipped with a high-speed generator with the goal of converting the mechanical energy of the microturbine into electrical energy. This ensures the microturbine operation in a given range on the characteristic of optimal fuel consumption. The article contains an analysis of the use of microturbine generators in vehicles; some constructive solutions are considered as well. An overview of vehicles with microturbine generators and their comparison with traditional internal combustion engines is given. The movement of the vehicle is carried out by one or several traction motors. More than ten developments of motor vehicles using the microturbine as an additional source of energy for vehicles with traction electric drive are already known in the world, including MiTRE (Microturbine Range Extender). Among such vehicles, one can name the Trolza "Ecobus" buses, Delta Hypercar supercar, Isuzu NPR trucks, Mack Truck, Kenworth.

scholarly journals Study on adaptability of rheological index of nano-PUA-modified asphalt based on geometric parameters of parallel plate

2021 ◽  
Vol 10 (1) ◽  
pp. 1801-1811
Author(s):  
Xiaolong Sun ◽  
Yikang Zhang ◽  
Qinyuan Peng ◽  
Junshen Yuan ◽  
Zhi Cang ◽  
...  
Keyword(s):  
High Temperature ◽  
Parallel Plate ◽  
High Speed ◽  
Geometric Parameters ◽  
Rheological Parameters ◽  
Test Results ◽  
Parallel Plates ◽  
Modified Asphalt ◽  
Temperature Performance ◽  
Rheological Test

Abstract To clarify the influence of geometric parameters of parallel plate on rheological properties of polyurea elastomer (PUA)-modified asphalt, nano-PUA powder was prepared, and nano-PUA powder modifier was modified by using high-speed shearing apparatus. The apparent viscosity of modified asphalt was evaluated by Brookfield viscosity. The rheological parameters of PUA-modified asphalt were determined by comparing the rheological test results of temperature scanning, frequency scanning, and multiple stress creep recover test using 8 and 25 mm parallel plates. Results indicated that the higher the content of nano-PUA modifier was, the better the high-temperature performance of asphalt would be. When using the 8 mm parallel plate, the high-temperature performance of modified asphalt was worse than that of matrix asphalt, and the PUA modifier would lead to a negative effect on the rheological property of asphalt. Regarding the 25 mm parallel plate, the high-temperature performance of modified asphalt was better than that of matrix asphalt, which was contrary to the results of 8 mm parallel plate. The rheological test results using 25 mm parallel plate were consistent with the results of Brookfield viscosity, indicating that 25 mm parallel plate was more suitable for evaluating the rheological performance of PUA-modified asphalt.

scholarly journals Quantitative 4D X-ray microtomography under extreme conditions: a case study on magma migration

2021 ◽  
Vol 28 (5) ◽  
Author(s):  
Elena Giovenco ◽  
Jean-Philippe Perrillat ◽  
Eglantine Boulard ◽  
Andrew King ◽  
Nicolas Guignot ◽  
...  
Keyword(s):  
Computed Tomography ◽  
High Pressure ◽  
High Temperature ◽  
High Speed ◽  
High Efficiency ◽  
Morphological Properties ◽  
Extreme Conditions ◽  
Temporal Dimension ◽  
Angular Aperture ◽  
X Ray

X-ray computed tomography (XCT) is a well known method for three-dimensional characterization of materials that is established as a powerful tool in high-pressure/high-temperature research. The optimization of synchrotron beamlines and the development of fast high-efficiency detectors now allow the addition of a temporal dimension to tomography studies under extreme conditions. Presented here is the experimental setup developed on the PSICHE beamline at SOLEIL to perform high-speed XCT in the Ultra-fast Tomography Paris–Edinburgh cell (UToPEc). The UToPEc is a compact panoramic (165° angular aperture) press optimized for fast tomography that can access 10 GPa and 1700°C. It is installed on a high-speed rotation stage (up to 360° s−1) and allows the acquisition of a full computed tomography (CT) image with micrometre spatial resolution within a second. This marks a major technical breakthrough for time-lapse XCT and the real-time visualization of evolving dynamic systems. In this paper, a practical step-by-step guide to the use of the technique is provided, from the collection of CT images and their reconstruction to performing quantitative analysis, while accounting for the constraints imposed by high-pressure and high-temperature experimentation. The tomographic series allows the tracking of key topological parameters such as phase fractions from 3D volumetric data, and also the evolution of morphological properties (e.g. volume, flatness, dip) of each selected entity. The potential of this 4D tomography is illustrated by percolation experiments of carbonate melts within solid silicates, relevant for magma transfers in the Earth's mantle.

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