SCIENTIFIC AND TECHNICAL AEROSPACE REPORTS
A Biweekly Publication of the National Aeronautics and Space Administration
VOLUME 43, ISSUE 18 - SEPTEMBER 09, 2005
07 AIRCRAFT PROPULSION AND POWER
Includes primary propulsion systems and related systems and components, e.g., gas turbine engines, compressors, and fuel systems; and onboard auxiliary power plants for aircraft.
For related information see also 20 Spacecraft Propulsion and Power; 28 Propellants and Fuels; and 44 Energy Production and Conversion.
20050204075 Clemson Univ., SC, USA
University Turbine Systems Research Program Summary and Directory. September 1992-June 2003
Golan, L. P.; Wenglarz, R. A.; Jul. 2004; 138 pp.; In English Report No.(s): DE2005-836410; No Copyright; Avail: Department of Energy Information Bridge
The South Carolina Institute for Energy Studies (SCIES), administratively housed at Clemson University, has participated in the advancement of combustion turbine technology for over a decade. The University Turbine Systems Research Program, previously referred to as the Advanced Gas Turbine Systems Research (AGTSR) program, has been administered by SCIES for the U.S. DOE during the 1992-2003 timeframe. The structure of the program is based on a concept presented to the DOE by Clemson University. Under the supervision of the DOE National Energy Technology Laboratory (NETL), the UTSR consortium brings together the engineering departments at leading U.S. universities and U.S. combustion turbine developers to provide a solid base of knowledge for the future generations of land-based gas turbines. In the UTSR program, an Industrial Review Board (IRB) (Appendix C) of gas turbine companies and related organizations defines needed gas turbine research. SCIES prepares yearly requests for university proposals to address the research needs identified by the IRB organizations. IRB technical representatives evaluate the university proposals and review progress reports from the awarded university projects. To accelerate technology transfer technical workshops are held to provide opportunities for university, industry and government officials to share comments and improve quality and relevancy of the research. To provide educational growth at the Universities, in addition to sponsored research, the UTSR provides faculty and student fellowships. The basis for all activities research, technology transfer, and education - is the DOE Turbine Program Plan and identification, through UTSR consortium group processes, technology needed to meet Program Goals that can be appropriately researched at Performing Member Universities. NTIS
Directories; Gas Turbines; Turbines
20050205696 Nippon Telegraph and Telephone Public Corp., Musashino, Japan
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Effects of Reputation System on Internet Auctions: Experimental Evaluation
Yoshikai, Noriaki; Takahashi, Hiroyuki; Usui, Yukihiro; International Conference on Advances in the Internet, Processing, Systems and Interdisciplinary Research (IPSI-2003); [2003]; 1 pp.; In English; See also 20050205660; Copyright; Avail: CASI; A01, Hardcopy; Available from CASI on CD-ROM only as part of the entire parent document
Outline: Many researchers have been investigating the creation and evaluation of trust on Internet Trades which must be operated under an anonymous and asymmetrical information environment. Reputation systems have been considered to be an effective technology for preventing the fraudulent trading. After considered the technical solutions to counter the weak points in the existing reputation systems, we have designed an experimental reputation system for an Internet-auction service. For four months, we have experimented the virtual auction registering more than 2000 people, by using this prototype on Internet. The experimental data show that a ‘lemons market’, in which honest traders and high quality goods are driven out of the trades by dishonest traders and low quality goods, certainly occurs on internet auctions under no reputation system , and that the reputation systems suppress the lemon market phenomena. And further study items are also discussed. Author
Experimentation; Thrust; Data Acquisition; Data
20050205811 NASA Glenn Research Center, Cleveland, OH, USA
One-Dimensional Spontaneous Raman Measurements of Temperature Made in a Gas Turbine Combustor
Hicks, Yolanda R.; Locke, Randy J.; DeGroot, Wilhelmus A.; Anderson, Robert C.; Research and Technology 2001; March 2002; 4 pp.; In English; No Copyright; Avail: CASI; A01, Hardcopy
The NASA Glenn Research Center is working with the aeronautics industry to develop highly fuel-efficient and environmentally friendly gas turbine combustor technology. This effort includes testing new hardware designs at conditions that simulate the high-temperature, high-pressure environment expected in the next-generation of high-performance engines. Glenn has the only facilities in which such tests can be performed. One aspect of these tests is the use of nonintrusive optical and laser diagnostics to measure combustion species concentration, fuel/air ratio, fuel drop size, and velocity, and to visualize the fuel injector spray pattern and some combustion species distributions. These data not only help designers to determine the efficacy of specific designs, but provide a database for computer modelers and enhance our understanding of the many processes that take place within a combustor. Until recently, we lacked one critical capability, the ability to measure temperature. This article summarizes our latest developments in that area. Recently, we demonstrated the first-ever use of spontaneous Raman scattering to measure combustion temperatures within the Advanced Subsonics Combustion Rig (ASCR) sector rig. We also established the highest rig pressure ever achieved for a continuous-flow combustor facility, 54.4 bar. The ASCR facility can provide operating pressures from 1 to 60 bar (60 atm). This photograph shows the Raman system setup next to the ASCR rig. The test was performed using a NASA-concept fuel injector and Jet-A fuel over a range of air inlet temperatures, pressures, and fuel/air ratios. Derived from text
Combustion Chambers; Gas Turbine Engines; Raman Spectra; Temperature Measurement; Combustion Temperature
20050205861 NASA Glenn Research Center, Cleveland, OH, USA
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Mystery of Foil Air Bearings for Oil-Free Turbomachinery Unlocked: Load Capacity Rule-of-Thumb Allows Simple Estimation of Performance
DellaCorte, Christopher; Valco, Mark J.; Research and Technology 2001; March 2002; 2 pp.; In English; No Copyright;Avail: CASI; A01, Hardcopy
The Oil-Free Turbomachinery team at the NASA Glenn Research Center has unlocked one of the mysteries surrounding foil air bearing performance. Foil air bearings are self-acting hydrodynamic bearings that use ambient air, or any fluid, as their lubricant. In operation, the motion of the shaft’s surface drags fluid into the bearing by viscous action, creating a pressurized lubricant film. This lubricating film separates the stationary foil bearing surface from the moving shaft and supports load. Foil bearings have been around for decades and are widely employed in the air cycle machines used for cabin pressurization and cooling aboard commercial jetliners. The Oil-Free Turbomachinery team is fostering the maturation of this technology for integration into advanced Oil-Free aircraft engines. Elimination of the engine oil system can significantly reduce weight and cost and could enable revolutionary new engine designs. Foil bearings, however, have complex elastic support structures (spring packs) that make the prediction of bearing performance, such as load capacity, difficult if not impossible. Researchers at Glenn recently found a link between foil bearing design and load capacity performance. The results have led to a simple rule-of-thumb that relates a bearing’s size, speed, and design to its load capacity. Early simple designs (Generation I) had simple elastic (spring) support elements, and performance was limited. More advanced bearings (Generation III) with elastic supports, in which the stiffness is varied locally to optimize gas film pressures, exhibit load capacities that are more than double those of the best previous designs. This is shown graphically in the figure. These more advanced bearings have enabled industry to introduce commercial Oil-Free gas-turbine-based electrical generators and are allowing the aeropropulsion industry to incorporate the technology into aircraft engines. The rule-of-thumb enables engine and bearing designers to easily size and select bearing technology for a new application and determine the level of complexity required in the bearings. This new understanding enables industry to assess the feasibility of new engine designs and provides critical guidance toward the future development of Oil-Free turbomachinery propulsion systems. Author
Turbomachinery; Lubrication; Foil Bearings; Engine Design; Performance Prediction; Shafts (Machine Elements)
20050205866 NASA Glenn Research Center, Cleveland, OH, USA
International Space Station Power System Model Validated
Hojnicki, Jeffrey S.; Delleur, Ann M.; Research and Technology 2001; March 2002; 3 pp.; In English; No Copyright; Avail: CASI; A01, Hardcopy
System Power Analysis for Capability Evaluation (SPACE) is a computer model of the International Space Station’s (ISS) Electric Power System (EPS) developed at the NASA Glenn Research Center. This uniquely integrated, detailed model can predict EPS capability, assess EPS performance during a given mission with a specified load demand, conduct what-if studies, and support on-orbit anomaly resolution. Derived from text
Computerized Simulation; Space Station Power Supplies
20050207429 Boeing Co., Canoga Park, CA, USA
Key Reliability Drivers of Liquid Propulsion Engines and A Reliability Model for Sensitivity Analysis
Huang, Zhao-Feng; Fint, Jeffry A.; Kuck, Frederick M.; [2005]; 12 pp.; In English; AIAA Conference, 10 July 2005, Tucson, AZ, USA Contract(s)/Grant(s): NAS8-01140; No Copyright; Avail: CASI; A03, Hardcopy
This paper is to address the in-flight reliability of a liquid propulsion engine system for a launch vehicle.We first establish a comprehensive list of system and sub-system reliability drivers for any liquid propulsion engine system. We then build a reliability model to parametrically analyze the impact of some reliability parameters. We present sensitivity analysis results for a selected subset of the key reliability drivers using the model. Reliability drivers identified include: number of engines for the liquid propulsion stage, single engine total reliability, engine operation duration, engine thrust size, reusability, engine de-rating or up-rating, engine-out design (including engine-out switching reliability, catastrophic fraction, preventable failure fraction, unnecessary shutdown fraction), propellant specific hazards, engine start and cutoff transient hazards, engine combustion cycles, vehicle and engine interface and interaction hazards, engine health management system, engine modification, engine ground start hold down with launch commit criteria, engine altitude start (1 in. start), Multiple altitude restart (less than 1 restart), component, subsystem and system design, manufacturing/ground operation support/pre and post flight check outs and inspection, extensiveness of the development program. We present some sensitivity analysis results for the following subset of the drivers: number of engines for the propulsion stage, single engine total reliability, engine operation duration, engine de-rating or up-rating requirements, engine-out design, catastrophic fraction, preventable failure fraction, unnecessary shutdown fraction, and engine health management system implementation (basic redlines and more advanced health management systems). Author
Reliability Analysis; Sensitivity Analysis; Liquid Propellant Rocket Engines; Propulsion
20050207438 NASA Glenn Research Center, Cleveland, OH, USA
Performance (Off-Design) Cycle Analysis for a Turbofan Engine With Interstage Turbine Burner
Liew, K. H.; Urip, E.; Yang, S. L.; Mattingly, J. D.; Marek, C. J.; July 2005; 80 pp.; In English Contract(s)/Grant(s): WBS 22-066-10-12 Report No.(s): NASA/TM-2005-213659; E-15149; No Copyright; Avail: CASI; A05, Hardcopy
This report presents the performance of a steady-state, dual-spool, separate-exhaust turbofan engine, with an interstage turbine burner (ITB) serving as a secondary combustor. The ITB, which is located in the transition duct between the high- and the low-pressure turbines, is a relatively new concept for increasing specific thrust and lowering pollutant emissions in modern jet-engine propulsion. A detailed off-design performance analysis of ITB engines is written in Microsoft(Registered Trademark) Excel (Redmond, Washington) macrocode with Visual Basic Application to calculate engine performances over the entire operating envelope. Several design-point engine cases are pre-selected using a parametric cycle-analysis code developed previously in Microsoft(Registered Trademark) Excel, for off-design analysis. The off-design code calculates engine performances (i.e. thrust and thrust-specific-fuel-consumption) at various flight conditions and throttle settings. Author
Design Analysis; Turbofan Engines; Steady State; Spools; Burners; Ducted Flow; Reliability Analysis
20050207442 NASA Glenn Research Center, Cleveland, OH, USA
Parametric (On-Design) Cycle Analysis for a Separate-Exhaust Turbofan Engine With Interstage Turbine Burner
Liew, K. H.; Urip, E.; Yang, S. L.; Siow, Y. K.; Marek, C. J.; July 2005; 54 pp.; In English Contract(s)/Grant(s): WBS 22-066-10-12 Report No.(s): NASA/TM-2005-213658; E-15148; No Copyright; Avail: CASI; A04, Hardcopy
Today's modern aircraft is based on air-breathing jet propulsion systems, which use moving fluids as substances to transform energy carried by the fluids into power. Throughout aero-vehicle evolution, improvements have been made to the engine efficiency and pollutants reduction. The major advantages associated with the addition of ITB are an increase in thermal efficiency and reduction in NOx emission. Lower temperature peak in the main combustor results in lower thermal NOx emission and lower amount of cooling air required. This study focuses on a parametric (on-design) cycle analysis of a dual-spool, separate-flow turbofan engine with an Interstage Turbine Burner (ITB). The ITB considered in this paper is a relatively new concept in modern jet engine propulsion. The ITB serves as a secondary combustor and is located between the high- and the low-pressure turbine, i.e., the transition duct. The objective of this study is to use design parameters, such as flight Mach number, compressor pressure ratio, fan pressure ratio, fan bypass ratio, and high-pressure turbine inlet temperature to obtain engine performance parameters, such as specific thrust and thrust specific fuel consumption. Results of this study can provide guidance in identifying the performance characteristics of various engine components, which can then be used to develop, analyze, integrate, and optimize the system performance of turbofan engines with an ITB. Visual Basic program, Microsoft Excel macrocode, and Microsoft Excel neuron code are used to facilitate Microsoft Excel software to plot engine performance versus engine design parameters. This program computes and plots the data sequentially without forcing users to open other types of plotting programs. A user s manual on how to use the program is also included in this report. Furthermore, this stand-alone program is written in conjunction with an off-design program which is an extension of this study. The computed result of a selected design-point engine will be exported to an engine reference data file that is required in off-design calculation. Author
Turbofan Engines; Engine Design; Exhaust Emission; Burners
20050207538 National Renewable Energy Lab., Golden, CO USA
Low Wind Speed Turbine Project Conceptual Design Study: Advanced Independent Pitch Control. (July 30, 2002-July 31, 2004) (Revised, Subcontractor Report)
Olsen, T.; Lang, E.; Hansen, A. C.; Cheney, M. C.; Quandt, G.; Dec. 2004; 132 pp.; In English Report No.(s): DE2005-15015117; No Copyright; Avail: Department of Energy Information Bridge
Advanced Energy Systems (AES) Inc. conducted a conceptual study of independent pitch control using inflow angle sensors. The control strategy combined input from turbine states (rotor speed, rotor azimuth, each blade pitch) with inflow angle measurements (each blade angle of attack at station 11 of 15) to derive blade pitch demand signals. The controller reduced loads sufficiently to allow a 10% rotor extension and to reduce cost of energy 6.3%. NTIS
Low Speed; Turbines; Wind Turbines; Wind Velocity; Windpower Utilization
20050207569 NASA Marshall Space Flight Center, Huntsville, AL, USA
Galium Electromagnetic (GEM) Thruster Concept and Design
Polzin, Kurt A.; Markusic, Thomas E.; [2005]; 2 pp.; In English; Joint Propulsion Conference, 11-13 Jul. 2005, Tucson, AZ, USA; No Copyright; Avail: CASI; A01, Hardcopy
We describe the design of a new type of two-stage pulsed electromagnetic accelerator, the gallium electromagnetic (GEM) thruster. A schematic illustration of the GEM thruster concept is given. In this concept, liquid gallium propellant is pumped into the first stage through a porous metal electrode using an electromagnetic pump. At a designated time, a pulsed discharge (approx. 10-50 J) is initiated in the first stage, ablating the liquid gallium from the porous electrode surface and ejecting a dense thermal gallium plasma into the second state. The presence of the gallium plasma in the second stage serves to trigger the high-energy (approx. 500 J), second-stage pulse which provides the primary electromagnetic (j x B) acceleration. Derived from text
Electromagnetic Acceleration; Liquid Rocket Propellants; Design Analysis
20050209936 NASA Marshall Space Flight Center, Huntsville, AL, USA
Electrodynamic Tether as a Thruster for MXER Studies
Khazanov, G. V.; Krivorutsky, E. N.; Sorensen, K.; [2005]; 1 pp.; In English; American Institute of Aeronautics and Astronautics (AIAA) Propulsion Conference, 11-13 Jul. 2005, Tucson, AZ, USA; No Copyright; Avail: Other Sources; Abstract Only
Electrodynamic propulsion based on the interaction of a conducting tether with the background magnetic field can be implemented across a range of system designs. Bare tethers, bare and insulated tethers with a balloon termination, and insulated tethers with a grid-sphere termination have been proposed for different applications. Electrodynamic tether as a thruster is currently proposed for the Momentum exchange Electrodynamic Reboost (MXER) Tether System that currently under development at NASA Marshal Space Flight Center. The choice of a tether design for a specific mission is based on the analysis of tether system performance. Different parameters describing tether performance such as system acceleration and efficiency can be calculated if the current distribution along the tether at the satellite trajectory is known. The code calculating the tether current collection for the bare and partly insulated tethers with the circular (wire) and rectangular (tape) cross-sections operating in the thrust mode has been developed and applied for MXER that is expected to operate in an equatorial elliptical orbit with perigee in the altitude range of 300-500km and apogee between 5000-8000km. The collected current is calculated as a function of the satellite velocity and the Earth s magnetic field, plasma parameters (plasma density and temperature), and tether parameters (tether length, the length of the bare segment, the type and the dimensions of the cross-section). The deviation of the collected current from the OML model due to the tether thickness and self-induced magnetic field (for tether with a circular cross-section) is taken into account. Author
Electrodynamics; Tethering; Thrust; Magnetic Fields
Source: NASA.
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