SCIENTIFIC UNDERSTANDING IN 2003 vs. 1999

Transcription

1 SCIENTIFIC UNDERSTANDING IN 2003 vs Green bars are updated values, with arrows updated uncertainty Waitz 32

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4 RADIATIVE IMBALANCE AT TROPOSPHERE DUE TO AIRCRAFT (IPCC Special Report on Aviation, 1999) 2003 Waitz 35

5 NOTES ON CLIMATE CHANGE IMPACTS Burning a gallon of fuel at 11km has about double the radiative impact of burning a gallon of fuel at sea-level Burning a gallon of fuel at 19km has about 5 times the impact at sea-level CO 2 is not the biggest global concern (potential impacts from contrails and cirrus clouds are greater). Large imbalance between northern and southern hemisphere Improving engine efficiency tends to make NOx and contrails worse High uncertainty 2003 Waitz 36

6 THE ROLE OF TECHNOLOGY: CHARACTERISTICS OF AVIATION SYSTEMS Safety critical Weight and volume limited Complex year development times $30M to $1B per unit capital costs 25 to 100 year usage in fleet Slow technology development and uptake 2003 Waitz 37

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8 COMMERCIAL vs. MILITARY FLEET TRENDS Demand growth for civil aviation (3.8%/year in US) Military fleet contraction Ops tempo (4.3/day commercial, 0.35/day military) Number of Aircraft Flights/day 2003 Waitz 40

9 FUEL CONSUMPTION TRENDS Aircraft responsible for 2%-3% of U.S fossil fuel use 2003 Waitz 41

10 COMMERCIAL AIRCRAFT EFFICIENCY Average Age = 13 yrs 2003 Waitz 42

11 MILITARY AIRCRAFT FUEL BURN Average Age 21 yrs 2003 Waitz 43

12 ENERGY EFFICIENCY Function of performance of entire system Aircraft technology (structures, aerodynamics, engines) Aircraft operations (stage length, fuel load, taxi/takeoff/landing time, flight altitude, delays, etc.) Airline operations (load factor) Each component of system can be examined independently for reduced fuel burn and impacts on local air quality and regional/global atmospheric effects 2003 Waitz 44

13 RANGE EQUATION Technology and Operations Stage Length VLD ( ) = ln + g SFC 1 W fuel W + W + W payload structure reserve = Technology = Operations W Efficiency ASK kg fuel payload W f g StageLength, W fuel Stagelength # seats = Use data to separate effects and understand influences of technology 2003 Waitz 45

14 TRENDS IN LOAD FACTOR Regional Jets Large Aircraft Load Factor Turboprops Year Babikian, Raffi, The Historical Fuel Efficiency Characteristics of Regional Aircraft From Technological, Operational, and Cost Perspectives, SM Thesis, Massachusetts Institute of Technology, June Waitz 46

15 FLIGHT AND GROUND DELAYS Ratio Airborne to Block Hours Minimum Flight to Airborne Hours Mininum Flight to Block Hours Year 2003 Waitz 47

16 25 HISTORICAL TRENDS Aerodynamic Efficiency F F /6000 L/Dmax F27 B B/300 S360 A /200 A RJ200/ER B B B /200/300 F100 BAC /400 B /ER ATR72 S340A MD11 DC10-30 L B /ER B B ATR42 BAE-ATP B /200 A L1011-1/100/200 D328 DC9-30 B DC10-10 MD80 & DC9-80 EMB120 B /600 DC10-40 B BAE /200/RJ70 B /231A BAE SA227 J41 J31 B777 DHC Babikian et al. (2002) Data Unavailable For: EMB-145 FH-227 CV-880 Nihon YS-11 BAE RJ85 SA-226 Turboprops Regional Jets Beech 1900 DHC Large Aircraft CV-580 L-188 CV-600 DHC Year 2003 Waitz 48

17 30 HISTORICAL TRENDS Engine Efficiency B B B /231A TSFC (mg/ns) BAC DC9-40 F /6000 BAE /200/RJ70 CV880 DC9-10 F DC9-50 B DC9-30 B /200 BAE MD80 & DC9-80 F100 RJ85 D328 EM170 DC10-30 L B /ER EMB145 B B /600 B F27 B /300 B RJ200/ER RJ700 L1011-1/100/200 B CV600 DC10-40 B /ER EMB135 MD11 DC10-10 A L188A-08/188C J31 A A /200 B777 CV580 SA226 B1900 SA227 DHC7 J41 S360 EMB120 ATR42 ATR72 D328 DHC8-100 BAE-ATP DHC8-300 DHC8-400 S340A 10 Babikian et al. (2002) 5 Turboprops Regional Jets Large Jets New Regional Jet Engines New Turboprop Engines Year 2003 Waitz 49

18 OEW/ MTOW F27 L188A-08/188C HISTORICAL TRENDS Structural Efficiency B /231A CV600 F BAC BAC DC9-10 FH227 DC10-10 B /200 DC9-40 SA226 BAE MD80 & DC9-80 L1011-1/100/200 F /6000 B /ER B /300 DC10-40 DHC7 DC9-50 S360 BAE /RJ70 CV880 L DC9-30 DC10-30 B B B DHC8-100 J31 SA227 ATR42 B1900 F100 B B EMB120 S340A A A B /ER BAE-ATP ATR72 J41 BAE A /200 B B /600 B MD11 D328 RJ85 RJ200/ER B777 DHC8-300 EMB Babikian et al. (2002) Turboprops Regional Jets Large Aircraft Year 2003 Waitz 50

19 6 EFFICIENCY Regional Jets Versus Turboprops Energy Usage (MJ/ASK) 5 Regional BAC Jet Fleet Regional CV880 4 Aircraft Fleet BAC CV600 F B1900 RJ200/ER 3 L188A-08/188C BAE RJ85 F /6000 F27 SA226 DHC7 J31 S360 SA227 BAE F100 2 J41 D328 Turboprop Fleet Babikian et al. (2002) BAE DHC8-100 S340A EMB120 1 ATR42 BAE-ATP Turboprops Regional Jets Year 2003 Waitz 51 DHC8-300 ATR72 EMB145

20 5 4 3 ENERGY USAGE Total Versus Cruise Babikian (2001) E U,CR Large Aircraft Total E U Large Aircraft E U,CR Regional Aircraft Total E U Regional Aircraft MJ/ASK Waitz Year 52

21 COMMERCIAL AIRCRAFT ENERGY INTENSITY TRENDS New technology energy intensity has been reduced 60% over last 40 years (jet age) 57% due to increases in engine efficiency 22% due to increases aerodynamic performance 17% due to load factor 4% due to other (structures, flight time efficiency, etc.) Structural efficiency constant (but traded for aero, passenger comfort, noise and SFC) Flight time efficiency constant (balance of capacity constraints and improved ATM) Fleet average energy intensity has been reduced 60% since 1968 Lags new technology by years 2003 Waitz 53

22 COMPARISON TO OTHER TRANSPORT MODES (Mark Janes, Boeing, in ICAO CAEP/5, 2002) 2003 Waitz 54

23 SHORT HAUL AIRCRAFT Facing Increasing Scrutiny E U (MJ/ASK) Jets Turboprops (Babikian, 2002) Royal Commission on the Environment (2002) deeply concerned at the prospect of continuing rapid increases in air transport, particularly an increase in short haul flights Aircraft introduced during or after 1980 only It is essential that the government should divert resources...encouraging and facilitating a modal shift from air to highspeed rail. Stage Length (km) 2003 Waitz 55

24 IMPACT OF NASA TECHNOLOGY SCENARIOS Global CO 2 Emitted per Year Billion Kg Effect of Proposed Environmental CO 2 Goals No Improvement Beyond 1997 Technology 25% Reduction Introduced in % Reduction Introduced in 2022 Zero CO2 Emission A/C Introduced in 2027 Zero CO2 Emission A/C Introduced in 2037 ( - GA and Military Emissions based on Boeing forecast - IPCC IS92a based ICAO demand model - No retrofit of technologies) U.S. DOE reported fuel use % Level Change Relative to 1990: +340% +230% +140% 250 Kyoto Protocol -20% Emission inventories Timing For Reductions Year +40% J. E. Rohde, NASA Waitz 56

25 IMPACTS OF MISSION REQUIREMENTS (NOx & Noise) Range/payload ~ fuel efficiency (commercial and military) High pressures and Thermal efficiency High NO temperatures x Propulsive efficiency Large mass flow with small velocity change Low Noise Maneuverability (military) High energy conversion per High thrust-per-weight, unit volume (high small compact engine temperatures and pressures) High NO x Supersonic flight (military) Low drag, small compact engine Small mass flow with large velocity change High Noise 2003 Waitz 57

26 NO x EMISSIONS TECHNOLOGY TRENDS 2003 Waitz 58

27 NO x EMISSIONS TRENDS 2003 Waitz 59

28 HISTORICAL FLEET CRUISE EMISSIONS PER PASSENGER PER KILOMETER 1.0 NO x Relative Emission / Pass-km 0.5 CO 2, H 2 O CO HC Year (DuBois, Boeing) 2003 Waitz 60

29 TECHNOLOGY AND EMISSIONS Improvements will not keep up with growth Aircraft typically have greater impact per unit of fuel burned Solutions for global climate will require unprecedented action (demand management/regulations, electric vehicles, contrail avoidance, etc.) Current understanding is that hydrogen makes problem worse High uncertainty relative to global impacts Engine efficiency improvements exacerbate NO x and contrails Significant improvements in structural efficiency, aero and operations are possible Improvements in these areas do not exacerbate other problems 2003 Waitz 61

30 SUMMARY Broad range of environmental impacts from aircraft Social costs of same order as industry profits Currently not internalized Current technology path and regulations not aligned with social costs Strong growth in demand Increasing public concern/regulatory stringency High uncertainty Many competing trades Environmental impacts Design, operations 2003 Waitz 62

31 SELECTED REFERENCES Babikian, R., Lukachko, S. P. and Waitz, I. A. "Historical Fuel Efficiency Characteristics of Regional Aircraft from Technological, Operational, and Cost Perspectives, Journal of Air Transport Management, Volume 8, No. 6, pp , Nov Lee, J. J., Lukachko, S. P., Waitz, I. A., and Schafer, A., Historical and Future Trends in Aircraft Performance, Cost and Emissions, Annual Review of Energy and the Environment, Volume 26, Waitz, I. A., Lukachko, S. P., and J. J. Lee, "Military Aviation and the Environment: Historical Trends and Comparison to Civil Aviation," AIAA , invited contribution to AIAA/ICAS International Air and Space Symposium and Exposition, Dayton, Ohio, July 14-17, Marks, D. H., et al., "Mobility 2001", World Business Council for Sustainable Development, Switzerland, Miake-Lye, R.C., Waitz, I.A., Fahey, D.W., Kolb, C.E., Wesoky, H.L., and Wey, C.C., Aviation and Climate Change, Aerospace America, September, Penner et al., United Nations Environment Programme, Intergovernmental Panel on Climate Change (IPCC), Special Report on Aviation and the Global Atmosphere, RCEP, The Environmental Effects of Civil Aircraft In Flight, Royal Commission on Environmental Pollution (RCEP), England, December, Waitz 63