In the realm of advanced aerospace research, understanding and mitigating the environmental impact of high-speed aircraft engines is crucial. Within this context, the CE-5B and CE-13 Combustion and Dynamics Facilities have emerged as pivotal resources for engineers and scientists aiming to innovate cleaner, more efficient propulsion technologies. Let’s delve into the specifics of these facilities, illustrating their capabilities, technological features, and the broader significance of their contributions to the field.
Combustion Research at CE-5B Facility
The CE-5B facility is dedicated to exploring combustion processes, with a particular focus on reducing nitrogen oxides (NOx) emissions. These emissions are significant contributors to air pollution and have adverse effects on both human health and the environment. The research conducted here supports the High-Speed Research and Advanced Subsonic Technology programs, highlighting its importance in advancing aviation technology.
One of the remarkable aspects of the CE-5B-1 test stand is its ability to accommodate sector arrangements of injector elements. This flexibility allows researchers to study the interactions between different elements or focus on larger single elements. The facility’s infrastructure includes a robust air supply system that delivers filtered combustion air at a pressure of 450 pounds per square inch gauge (psig). This air is heated using a non-vitiated heater, capable of raising temperatures up to 1,100°F and supporting airflows as high as 20 pounds per second.
The combustion air flows through the test section, where it is quenched with water spray before being discharged to either the altitude or atmospheric exhaust system. The preheater, crucial for preparing the air, uses four J-47 burner cans fueled by natural gas. Research hardware within the facility typically utilizes aviation-grade fuels like ASTM Jet-A, JP-5, or JP-8.
CE-5B-1 Special Features
Beyond the standard instrumentation, CE-5B-1 is equipped with water-cooled gas sampling rakes in the downstream section, allowing for particulate measurements at the combustion exit. The combustor section’s optical accessibility enables cutting-edge, non-intrusive laser-based diagnostics on both reacting and non-reacting flowfields. Techniques employed include planar laser-induced fluorescence (PLIF) imaging, planar Mie scattering, phase/Doppler particle analysis (PDPA), focused Schlieren imaging, and light sheet photography. These advanced diagnostic methods provide unparalleled insights into the combustion process, facilitating a deeper understanding of the phenomena involved.
CE-5B-1 Facility Capabilities
In terms of operational parameters, the CE-5B-1 facility boasts impressive capabilities:
- Inlet Air Supply Pressure: 450 psig
- Inlet Air Temperature: Starting at 100°F, preheated up to 1,350°F
- Inlet Airflow: 20 pounds per second (available), with specific flow ranges for different stands
- Exhaust Options: Atmospheric or 20-26 inches of mercury (Hg)
- Rig Pressure:
- Without Windows: 275 psig for Stand 1 and 400 psig for Stand 2
- With Windows: 250 psig for Stand 1 and 275 psig for Stand 2
- Fuel Flow (JP-8): 7 gallons per minute at 400-900 psig
CE-5B-2: Exploring Innovative Combustion Concepts
The CE-5B-2 test stand complements the capabilities of CE-5B-1 by focusing on advanced combustion concepts such as lean-premixed-prevaporized (LPP) and lean-direct-injection (LDI). These approaches aim to develop low-NOx combustors, essential for high-speed research and advanced subsonic applications. The combustion flame tube can be configured in both square and round sections, accommodating various gas sampling probes and optical windows for non-intrusive measurements.
CE-5B-2 Special Features
Similar to CE-5B-1, CE-5B-2 offers laser-based diagnostics for analyzing reacting and non-reacting flowfields. A comprehensive data acquisition system supports both test positions, ensuring accurate and reliable data collection. These features are critical for advancing our understanding of combustion processes and optimizing engine performance.
CE-13 Combustion and Dynamics Facility (CDF)
The CE-13 CDF is instrumental in examining methods to reduce NOx and particulate emissions from air-breathing aircraft engines. This facility operates at low pressures, making it ideal for studying fuel-air injection schemes and their effects on fluid mixing, emissions, dynamics, and flame stability. Jet-A is the primary fuel used, with alternate jet fuels tested to assess their impact.
CE-13C Special Features
Research hardware in CE-13C is designed for vertical downward flow, with preheated air supplied to the inlet stream conditioner and fuel injector. The mixed air and fuel mixture moves through the combustor, where combustion is observed through specialized windows. Products of combustion pass through an emission sampling ring and exit via a choke nozzle. The facility’s laser room employs various lasers to characterize fuel injection, combustor flow, and combustion species.
CE-13C Facility Capabilities
Key operational parameters of CE-13C include:
- Inlet Air Pressure: Ambient to 75 psia
- Inlet Air Temperature: Ambient to 1,000°F
- Inlet Airflow: 0.0 – 1.0 pounds per second
- Jet Fuel Supply: Two circuits with varying flow rates and pressures
- Exhaust: Atmospheric
- Cooling Systems: Peripheral and quench cooling systems with specific flow rates
SE-5 High-Pressure Combustion Diagnostics (HPCD) Laboratory
The SE-5 HPCD laboratory is a cutting-edge facility designed to support advanced diagnostics development and national standard calibrations. This high-pressure rig features single-element fuel injection burners and emission sampling ports, allowing for precise measurements and analysis. Optical access to the primary reaction zone is provided by UV-grade fused silica windows, enabling non-intrusive optical diagnostics like laser Raman spectroscopy and high-speed imaging.
SE-5 Special Features
The SE-5 facility is unique, as it is the only continuous-flow, hydrogen-capable 60-atm rig globally with optical access. This feature offers researchers unprecedented insights into flame conditions, simulating environments within future advanced aircraft engines’ ultra-high pressure-ratio combustion chambers.
SE-5 Facility Capabilities
- Cooling Capacity: 4,000,000 BTU/hr
- Equivalence Ratio Variance: 0.2 to 4
- Fuel Flow Rate: Limited by cooling capacity
- Operating Pressure: 30 atm nominal, 60 atm maximum
- Cooling and Quenching Airflow: Specific maximum flow rates
Particulate Aerosol Laboratory (PAL)
The PAL facility studies aerosols under simulated upper atmospheric conditions, reaching altitudes of up to 55,000 feet at -135°F. It provides a versatile testing environment for alternative fuels, additives, and combustion concepts. The facility is optimized for real-time mixing of alternative fuel additives and baseline fuels, with advanced cloud simulation capabilities.
SE-11 Special Features
The SE-11 facility offers particulate emission sample extraction, equipped with optical access for diagnostics like Mie scattering and video imaging. Particulate measurements include size and number density, with adjustable optical measurement plane locations relative to the chamber nozzle exit.
SE-11 Facility Capabilities
- Burner Fuel Flow Rate: 0.2 – 9.9 ml/min
- Burner Air: Filtered and dried, with heated bypass air available
- Burner Exhaust Gas Temperature: Up to 1,000°F
- Particle Sizing Range: 2.5-1,000 nm
- Gas Composition Analyzer: CO, CO₂, O₂
Conclusion
NASA’s Glenn Research Center in Cleveland hosts these state-of-the-art facilities, offering ground test capabilities to industry, government, and academia. For those seeking to push the boundaries of aerospace technology and environmental sustainability, these facilities provide the resources and expertise necessary to achieve groundbreaking advancements in combustion research. For more information on utilizing these testing capabilities, interested parties are encouraged to reach out to NASA’s Glenn Research Center.
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