# Presentation: 319332

## 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 CO2 based on an overall fuel savings goal of at least 8%
- Technology Readiness to the Component Level

## Ultra Efficient Engine Technology

- FlameTube
- Sector
- Full Annular
- Core Engine?
- Particulates/ Aerosols & other Emittents
- CMC Liner @ 10%  Cooling

- 2400°F Uncooled CMC materials
- Adv. Materials to enable 3100°F Turbine Rotor Inlet Temp. w/ 15% Cooling (3100°F T41 @ 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**

- Combustion

- Turbomachinery

- 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, 10000 ft Field Length**
**Fuel Burn “Waterfall” - **Scenario-Based Vehicle Technologies

**Fuel Burn = 205,800 lbs**
**1995 EIS Technology**

**-124,100 lbs (-60%)**

**Fuel Burn = 81,700 lbs**

**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**