NASA Environmental Programs—Aviation Emissions: A Perspective from Academia Professor Ian A. Waitz Massachusetts Institute of Technology 4th Environmental Compatibility Assessment Workshop Colorado Springs, CO August 12-13, 1999

OUTLINE Recasting the question NASA’s Ultra Efficient Engine Program - General comments - Does it respond to prior ECoA recommendations? Guidance for strategic planning and implementation - Goal-driven implementation, entertain & grow new ideas - Prioritize based on importance and uniqueness of NASA contribution

RECASTING THE QUESTION As posed: “What opportunities exist that current NASA programs are not addressing?” Difficulty lies in finding funding, not opportunities Funding is not sufficient to effectively respond to all needs/opportunities As recast: “How can limited funding be used most effectively to respond to needs for emissions reduction?”

Ultra-Efficient Engine Technology Program Goals: Increased performance to enable and enhance a wide range of revolutionary aircraft from small to large, and over a wide range of flight speeds Address local air quality concerns as well as addressing potential ozone depletion by developing technology for 70% NOx emissions reduction at take-off and landing conditions, and also technology to enable aircraft to not impact the ozone layer during cruise operation Address long term aviation growth potential without impact on climate by providing technology for dramatic increases in efficiency to enable reductions in CO 2 based on an overall fuel savings goal of at least 8% Technology Readiness to the Component Level

Ultra-Low NOx Combustors research and analysis –FlameTube –Sector –Full Annular –Core Engine? Particulates/ Aerosols & other Emittents CMC 10% Cooling 2400°F Uncooled CMC materials Adv. Materials to enable 3100°F Turbine Rotor Inlet Temp. w/ 15% Cooling (3100°F 15% Wac/Wa3) –Disk –Airfoils Blade Vane Light Weight Nozzle Structure Environmentally Friendly PMC with 600°F capability Fans, 3.5 PR at 1500 ft/sec Highly Loaded Compressors –16:1 in 4 stages –55 OPR/3100°F TRIT Highly Loaded/ Coupled HP/LP Turbines Analytical and Experimental solutions for Propulsion/Airframe Integration to Enable UHBPR and Advanced Concepts Simulations to Reduce Testing Assessment including Environmental Impact INVESTMENT AREAS: Ultra Efficient Engine Technology CombustionTurbomachinery Propulsion System Integration & Assessment Materials & Structures

COMMENTS ON NASA UEETP An engine program, not an emissions reduction program – Propulsion is not the only “key to finding solutions for noise, emissions and reliability” (see waterfall chart, also IPCC report) – Parallel programs at other centers? “Contracts, but limited” not the best way to achieve objectives – Open all research to competition and peer review, allow free-market to work – Thus, increase the quality of the research (more for the $) Why not investigate “design for retrofit”, “closed-cycle cooling concepts”, “oil-free bearings”, “robust design”, “better costing methods”, etc.? By what mechanisms will new ideas be admitted?

325 PAX CONVENTIONAL SUBSONIC TRANSPORT 2-Engine, 6500 nmi Design Range, ft Field Length Fuel Burn “Waterfall” - Scenario-Based Vehicle Technologies Fuel Burn = 205,800 lbs 1995 EIS Technology -124,100 lbs (-60%) SYSTEMS  Fuel Burn = - 8% Fuel Burn = 81,700 lbs PROPULSION  Fuel Burn = - 19% STRUCTURES  Fuel Burn = - 24% Laminar Flow Control Design Optimization Excrescence Drag Reduction AERODYNAMICS  Fuel Burn = - 9% Composite Wing & Tails Composite Fuselage Light Weight Landing Gear Advanced Metals Aeroelastic Tailoring (AR) Propulsion Aero-Mechanical Design Propulsion Hot Section Propulsion Materials Propulsion Secondary Systems Relaxed Static Stability All Flying Control Surfaces Fly-By-Light/Power-By-Wire High Performance Navigation Intelligent Flight Systems Mark Guynn, NASA LaRC

COMMENTS ON NASA UEETP Many consensus recommendations from prior ECoA Workshops are apparent in UEETP planning document (3/99): – Near-term vs. long term balance – Global and local effects Some consensus recommendations not strongly expressed in planning document: – Continuing communication/coordination between stakeholders – Consideration of market acceptance, economics, etc. – System-level analysis – Fuel efficiency and operations are low hanging fruit for near-term

GUIDANCE FOR STRATEGIC PLANNING AND IMPLEMENTATION Funding is limited, need to prioritize and leverage Suggested bases for prioritization: – Importance – Uniqueness of NASA role/contribution – Cost/benefit – Core competencies

PRIORITIZING FOR EMISSIONS REDUCTION - Importance - Aero, structures, operations -- same order of importance as propulsion for overall efficiency benefits Focus on most significant market segment – Stop all research on supersonic biz jets, general aviation, perhaps even commuter and helicopters Human resource development – Many new ideas will come from people trained in universities – People (as product) more important than research (as product) from universities – ~ 30% of aeronautics funding at MIT is from NASA # of grad students is set by funding feedstock for the industry/NASA – Must recognize and capitalize on NASA’s role in education

PRIORITIZING FOR EMISSIONS REDUCTION - Uniqueness of NASA role/contribution - Industry focus is near-term, profit-driven NASA funds limited NASA must focus on areas not addressed by industry – Understanding/assessing potential impacts – Education Feedstock to meet future challenges – Far-term “game-changing” concepts New configurations Aspirated compressors/turbines Design for retrofit? Closed-cycle cooling? Etc.... – Communication and coordination

UNDERSTANDING/ASSESSING POTENTIAL IMPACTS Uncertainty is high relative to impacts and trade-offs Potential to do the wrong thing – Ineffective regulations, poorly invested technology $, international discord, etc. Industry must respond only to profit incentive NASA must ensure that understanding is sufficient so that EPA/FAA/ICAO rules are not arbitrary, capricious, ineffective, etc. With appropriate rule-making industry, communities, etc. will respond to reduce emissions Very high leverage work – Most technology development $ held in industry - need to have these $ used appropriately and effectively

SUMMARY NASA Emissions Reduction Programs – NASA taking lead role – Need for prioritization is even greater as funding is reduced – Currently engine-centric Greater focus on important items where NASA role is unique – Address most significant market segment only (short and long-haul commercial transport) – Long-term, high-risk solutions – Assessment and understanding of impacts is high-leverage activity – Education – Coordination and communication - Goal-driven implementation, entertain & grow new ideas – Increase competition to increase research quality