SCIENTIFIC AND TECHNICAL AEROSPACE REPORTS

A Biweekly Publication of the National Aeronautics and Space Administration
VOLUME 44, ISSUE 9 - MAY 5, 2006

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 .

20060011322 Alzeta Corp., Santa Clara, CA, USA

Development and Demonstration of an Ultra-Low NOx Combustor for Gas Turbine Engines

Apr. 2005; 92 pp.; In English Report No.(s): DE2006-840382; No Copyright; Avail.: National Technical Information Service (NTIS)

Alzeta Corporation has developed surface-stabilized fuel injectors for use with lean premixed combustors which provide extended turndown and ultra-low NOx emission performance. These injectors use a patented technique to form interacting radiant and blue-flame zones immediately above a selectively-perforated porous metal surface. This allows stable operation at low reaction temperatures. This technology is being commercialized under the product name nanoSTAR. Initial tests demonstrated low NOx emissions but, were limited by flashback failure of the injectors. The weld seams required to form cylindrical injectors from flat sheet material were identified as the cause of the failures. The approach for this project was to first develop new fabrication methods to produce injectors without weld seams, verify similar emissions performance to the original flat sheet material and then develop products for microturbines and small gas turbines along parallel development paths. A 37 month project was completed to develop and test a surface stabilized combustion system for gas turbine applications. New fabrication techniques developed removed a technological barrier to the success of the product by elimination of conductive weld seams from the injector surface. The injectors demonstrated ultra low emissions in rig tests conducted under gas turbine operating conditions. The ability for injectors to share a common combustion chamber allowing for deployment in annular combustion liner was also demonstrated. Some further development is required to resolve integration issues related to specific engine constraints, but the nanoSTAR technology has clearly demonstrated its low emissions potential. NTIS

Combustion Chambers; Gas Turbine Engines; Nitrogen Oxides

20060011596 Test Wing (0412th), Edwards AFB, CA, USA

Knowledge Gained from F/A-22/F119 Propulsion System Ground and Flight Test Analysis

Web, Allan T.; Kidman, David S.; Malloy, Donald J.; Flight Test: Sharing Knowledge and Experience; May 2005, pp. 23-2 - 23-14; In English; See also 20060011579; Original contains color and black and white illustrations; Copyright; Avail.: CASI: A03, Hardcopy; Available from CASI on CD-ROM only as part of the entire parent document

This paper describes the teaming strategy between the Air Force s two major propulsion test centers, the Arnold Engineering Development Center (AEDC), and the Air Force Flight Test Center (AFFTC) to evolve new paradigms and approaches for cost sharing and sharing knowledge for risk management in the development of new aero-propulsion systems. The AEDC is responsible for the ground-based altitude development of current and future propulsion systems, and the AFFTC is responsible for in-flight development testing of installed propulsion systems. I m Allan Webb, Chief of the Propulsion Integration Branch at the Air Force Flight Test Center at Edwards Air Force Base, CA and I will be presenting the introductory and summary slides addressing knowledge gained from F/A-22/F119 propulsion system ground and flight test analysis. Dr. Donald Malloy from the Arnold Engineering Development Center in Tennessee will discuss propulsion system ground and flight test analysis procedures for the F119 powered F/A-22 aircraft. Author

Propulsion System Configurations; Propulsion System Performance; Aircraft Engines; Flight Tests; Ground Tests; Product Development

20060012147 Pratt and Whitney Aircraft, East Hartford, CT, USA

Engine Company Evaluation of Feasibility of Aircraft Retrofit Water-Injected Turbomachines

Becker, Arthur; April 2006; 35 pp.; In English; Original contains color illustrations Contract(s)/Grant(s): NNC04QB58P Report No.(s): NASA/CR-2006-213871; E-15241; No Copyright; Avail.: CASI: A03, Hardcopy

This study supports the NASA Glenn Research Center and the U.S. Air Force Research Laboratory in their efforts to evaluate the effect of water injection on aircraft engine performance and emissions. In this study, water is only injected during the takeoff and initial climb phase of a flight. There is no water injection during engine start or ground operations, nor during climb, cruise, descent, or landing. This study determined the maintenance benefit of water injection during takeoff and initial climb and evaluated the feasibility of retrofitting a current production engine, the PW4062 (Pratt & Whitney, East Hartford, CT), with a water injection system. Predicted NO(x) emissions based on a 1:1 water-tofuel ratio are likely to be reduced between 30 to 60 percent in Environmental Protection Agency parameter (EPAP). The maintenance cost benefit for an idealized combustor water injection system installed on a PW4062 engine in a Boeing 747-400ER aircraft (The Boeing Company, Chicago, IL) is computed to be $22 per engine flight hour (EFH). Adding water injection as a retrofit kit would cost up to $375,000 per engine because of the required modifications to the fuel system and addition of the water supply system. There would also be significant nonrecurring costs associated with the development and certification of the system that may drive the system price beyond affordability. Author

Water Injection; Turbomachinery; Retrofitting; Cost Effectiveness; Combustion Products; Exhaust Gases; Exhaust Emission; Fuel Systems

Source: NASA