geae’s expectations for the nasa qat program geae’s follow-up to the qat workshop in dallas...

GEAE’s Expectations for the NASA QAT Program

GEAE’s follow-up to the QAT workshop

in Dallas 11-12 April ,2000

GE Aircraft Engines

x

QAT/25 Apr 00 GE Aircraft Engines

GE ExpectationsGE Expectationsfor the for the

NASA Quiet Aircraft Technology NASA Quiet Aircraft Technology Program Program

Philip GliebeGE Aircraft Engines

NASA QAT WorkshopDallas, TX

April 11, 2000

The next 8 charts were presented by Phil Gliebe at QAT Dallas


GE Goal

Sid

eli

ne

Dis

tan

ce

, k

m

1997 Technology

2

1

0

-1

-2

Distance From Brake Release, km

65% Reduction in85 dBA Contour Area

-1 0 1 2 3 4

GE Views on Acoustics Technology GoalsGE Views on Acoustics Technology Goals

EPNL(dB)

London Airport Criteria

80

85

90

95

100

105

Sideline Cutback Approach

- 1997 Technology

- GE Goal

QC 0.5

MinimalSleep

Disturbance

Goals Below Minimal Sleep-disturbance LevelsGoals Below Minimal Sleep-disturbance Levels


dBA vs. EPNL CorrelationStage 3 Aircraft Certification Noise Levels

y = 1.0426x - 15.645

R2 = 0.8319

40

50

60

70

80

90

100

40 50 60 70 80 90 100 110

Effective Perceived Noise Level, EPNdB

A-Weighted Sound Level, dBASample Cert. Data

Linear Regression

Suburban Living Room Background Noise Level

Typical Business Office Noise Level

Conversational Speech Noise Level

Street Corner Average Traffic Noise Level

Rustling Leaves Noise Level

Blow-Dryer, Chain Saw, Subway Train

Power Lawn Mower, Passing Motorcycle

Factory Noise Level, Electric Shaver

Garbage Disposal, Vacuum Cleaner

Aircraft Noise Level Goals Should be Compatible With Competing Background Noise Levels - 65 to 75 dBA or 80 to 90 EPNdB


• Sleep Disturbance (London Airports), Background Sources Important• Engine & Airframe Noise Reduction Required

Noise Goal Selection Criteria - Future Aircraft

70

75

80

85

90

95

100

105

Sideline Cutback Approach

EPNL(dB)

- 1997 Technology - GE Goal - NASA 3-Pillar Goal - Est. Airframe Noise

QC 0.5

MinimalSleep

DisturbanceGround Traffic

Noise Level

ConversationalSpeech Level

Business OfficeNoise Level

Suburban Home Noise

Level

Factory Noise,Lawn mower,

MotorcycleNoise Level


Acoustics Technology Current State-of-the-ArtAcoustics Technology Current State-of-the-Art

Normalized EPNL Trends

60

65

70

75

80

85

90

95

100

0 200 400 600 800 1000 1200 1400

Specific Thrust (Vmix), ft/sec

No

rmal

ized

EP

NL

, d

B

GE90CF6CMF56CF34RegressionUpper 85% CILower 85% CI

Approach

Cutback

Sideline

GEAEGoals

1997 Technology

10 to 15 dB Challenge Relative to 1997 Technology Noise Levels10 to 15 dB Challenge Relative to 1997 Technology Noise Levels


ADVANCED ENGINE ACOUSTICS TECHNOLOGYARCHITECTURE CONSTRAINTS

• Specific Thrust - If Too High, Jet Noise Controls, and Jet Noise is Hard to Reduce

• Fan Tip Speed - If Too High, I.e., Transonic or Supersonic, Rotor Alone Noise Controls, Reduces Effectiveness of Other Source Reductions (Swept/Leaned Vanes, etc.)

Technology Challenge: Aggressive Specific Thrust and Fan Tip Speed - Requires Innovative, Physics-

Based Jet Noise and Fan Noise Reductions


ADVANCED ENGINE ACOUSTICS TECHNOLOGYPOTENTIAL NOISE REDUCTION CONCEPTS

• Balanced Cycle: Lower Jet Noise To Point Where Low-Cost, Low-Penalty Reduction Methods (e.g., Advanced Chevrons) Make Jet Noise Insignificant Contributor

• Innovative Fan Noise Reduction:- Fan Rotor Wake Mixing Control- Hybrid Active/Passive Liners- Exhaust Duct Shaping- Low Vane-Count, Swept OGV’s- Swept Fans- Zoned-Impedance Liners- Two-Stage, Low Tip-Speed Fan


GE Expectations for Proposed NASA“Quiet Aircraft Technology Development Program”

Significant Engine Noise Source Technology Content- Physics-based research and modeling of noise mechanisms- Exploration of noise mechanisms reduction (not just propulsion/airframe architectures which are quieter)

A Balanced Approach- Develop technologies compatible with lower emissions technologies- Develop technologies compatible with airline customer value

Set consistent goals- Consistent with envisioned program resources- Consistent with reasonable probability of success in 5 years- Define success in terms of outcomes that industry can use and airline customers can afford.


GEAE QAT Expectations: After attending the Dallas W/S

• Revolutionary concepts for Far Term - 10% of funding- New configurations, cycles, etc

• Revolutionary concepts for Mid term - 40% of funding- Engines and Aircraft entering service in 2007-2020

• Revolutionary Concepts for Current and near term - 50% of funding- Address technical barriers to meet current and near term noise

regulations.

Portfolio Diversity/Work splits:

Funding/Work splits necessary to meet noise goals and obtain Cost Sharing


GEAE QAT Expectations

• Low Noise Operations -- 10% of funding

• Engines Systems --- 30% of funding

• Modeling and Integration-- 30% of funding

• Airframe Systems ---- 30 % of funding

Work Focus Area Funding Splits:



• Follow the AST Noise format plus:- Steering committee with academia and UEET- Technical committee all parties plus UEET and Military- International interface committee ( NASA and US Industry plus

European Union and European Industry)

QAT Structure:



• GEAE believes that the NASA pillar goals for Noise need clarification

• GEAE interprets the NASA 3-Pillar Goals for Noise - reducing perceived noise by a factor of two in 10 years and by a factor of 4 in 20 (or 25) years - to mean 3 dB reduction and 6 dB reduction, from a 1997 base ( GE90 )

• GEAE does not interpret the NASA Pillar Goals to be based on factors of 2 and 4 reduction in “Total Perceived Noisiness” or “Total Loudness” in units of “noys” - it is assumed to be based on the effective acoustic power per event corresponding to EPNL [ WEPNL = 10(EPNL/10) ]

• GEAE supports setting a absolute stretch-goal of 85 EPNdB or a 10 dB-down goal for the first five year QAT program with the understanding that the 85 EPNdB or 10 dB-down goal will not be achieved until the 2007 to 2010 time period, and therefore requires a funded follow-on 2nd five year QAT program

Goals:

geae’s expectations for the nasa qat program geae’s follow-up to the qat workshop in dallas...

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