National Aeronautics and Space Administration

High Altitude Emissions

Dan Bulzan

Associate Principal

Investigator

NASA Glenn Research Center

NASA Green Aviation

Summit

September 8-9, 2010

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Lee, et al, Aviation and Global Change in the 21st Century, Atmospheric Environment

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growth

Particulate Matter Formation Processes from Aviation Emissions

aircraft

exhaust

H2O

SO3

H2SO4

soot

particles

binary

collision nucleation

chemistry

ambient mixing/dilution

condensation

H2O

H2O H2SO4

Hydrocarbons

(HCs)

HCs

coated soot particles

~30-100 nm diameter

Nucleation/growth

mode particles

<20 nm diametersoot

activation/scavenging

Environmental impacts of particulate emissions are currently poorly

understood Aerodyne

Research, Inc.3

Capability Metrics for Future Supersonic AircraftNASA’s Initial View

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Effect of NOx Emissions on Ozone at High Altitude

•Effect of NOx Emissions on Ozone are different for Supersonics compared to Subsonics due to higher altitude flight in lower Stratosphere

•Stratospheric Ozone also predicted to have a negative radiative forcing function as opposed to postive for Tropospheric ozone

NASA CR-2005-

213646

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Reduce/Eliminate Impact of Aviation Emissions

Approach

• Reduce NOx emissions

• Reduce soot

• Reduce fuel consumption

• Alternative Fuels for Life Cycle CO2 Reductions

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Research Areas• Emissions Prediction and Modeling

– Physics-based model development for combustion CFD codes for improved supersonic cruise emissions predictions

• Diagnostics and Validation Experiments

– Laser-based diagnostics development for quantitative major species and temperature measurements

CFD code validation experiments–

• Low Emission Concepts

– Low NOx and emission concept development

Active combustion control–

• High Temperature Sensors

– High temperature/frequency fuel actuators and pressure sensor development for active combustion control

• Atmospheric Studies (Particle Altitude Simulation Laboratory)

– Exhaust plume particulate measurements at Sea Level and Altitude conditions

Effects of particulates and sulfur on contrail formation–

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NASA Facilities

SE-11

Particle

Altitude

Simulation

Laboratory

CE-5 High

Pressure

Flametube SE-5 High-Pressure

Laboratory Scale Burner

CE-24

Well Stirred

Reactor

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Combustion Code Validation

SE-5 High-Pressure Combustion

SE-5 High-Pressure Combustion Diagnostics Facility.

Pressure <30 atm, Preheated air <800F.

Gaseous and liquid fuels

Single-Element LDI Burner

Measured Temperatures in Reference Flames

Polarization-resolved Raman spectroscopy developed for major species and temperature measurements Improved accuracy in multi-scalar measurements Optical interference-free detection

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Emissions Prediction And ModelingHeinz Pitsch, Stanford University

Soot Model Development:

Soot Number Density In LES

Of Delft Flame III

Combustion Model

Development: LES Of

NASA’s LDI Combustor

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PW Supersonic Transport Engine LTO+Cruise Cycle:

Challenge : EINOx < 5 @ Supersonic CruiseHigh inlet temperature and fuel/air ratio combine in 5 EINOx challenge

High inlet temperatures challenge all low-NOx burners -- LPP, LDI, RQL:• Increased burning temperatures• Earlier combustion initiation (reduced mixing time), in combustor• Increased propensity for autoignition & flashback, within injector

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Low NOx Combustion Concepts

Counter-Rotating Externally-

Staged Swirler (CRESS)

Low Emissions

Advanced

Premixing

(LEAP)

Multipoint Lean Direct Injection

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SummaryDiverse research program designed to reduce the effects of aviation on

high altitude emissions

• Improve Computational Modeling Capability to assist the development of lower emissions combustors

• Develop Low Emission Combustor Concepts that reduce NOx Emissions throughout the entire engine cycle

• Develop Combustor concepts that reduce particulate emissions

• Improve efficiency of both airframe and engine to reduce fuel burn

• Assist in the development of Alternative Fuels that have the potential to reduce both pollutant emissions and the carbon footprint of aviation

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