# Presentation: 144693

## 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***

## GE Expectations

***for the ***
*** ******NASA Quiet Aircraft Technology Program  ***

*Philip Gliebe**GE Aircraft Engines**NASA QAT Workshop**Dallas, TX*
*April 11, 2000*

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

## GE Views on Acoustics Technology Goals

***GE 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**

**Minimal**

**Sleep**

**Disturbance**

***Goals Below Minimal Sleep-disturbance Levels***

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

***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***

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

***Acoustics 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**

**Normalized EPNL, dB**

**GE90**

**CF6**

**CMF56**

**CF34**

**Regression**

**Upper 85% CI**

**Lower 85% CI**

**Approach**

**Cutback**

**Sideline**

**GEAE**

**Goals**

**1997 Technology **

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

## ADVANCED ENGINE ACOUSTICS TECHNOLOGY

***ARCHITECTURE 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 TECHNOLOGY

***POTENTIAL 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:***

## GEAE QAT Expectations

- 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 QAT Expectations

- 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:***_