FUNDAMENTAL NOISE

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FUNDAMENTAL NOISE NASA GLENN RESEARCH
CENTER Loretta Shaw, Subsonic Systems
Office Dennis Huff, Acoustic Branch Chief
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Aerospace Propulsion and Power Base Program
Propulsion Fundamentals Research Project
Objective to provide support for new
high-risk, high-payoff activities that are of
long term strategic importance
Fundamental Noise
Objective Develop advanced concepts to reduce
subsonic engine fan, jet and core noise.
Aeroacoustic Propulsion Laboratory
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Aerospace Propulsion and Power Base Program
Fundamental Noise Approach in FY00

• Jet Noise Experiments
• - Provide fundamental insight into physics of
  jet noise
• generation and propagation

Small Hot Acoustic Jet Rig

• Jet Noise Prediction
• - Develop next generation jet noise prediction
  tools based on
• modeling and Computational Aeroacoustics

MGBK prediction
Data

• Fan Noise Prediction
• - Develop the next generation fan noise
  prediction tools
• based on Computational Aeroacoustics

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Aerospace Propulsion and Power Base Program
Fundamental Noise Approach in FY00 Continued

• Micro-blown Acoustic Aft-duct Splitter
• - Demonstrate the reduction of skin friction
  and aft duct fan noise with a micro-blown
• aft duct splitter

• Active Control of Fan Broadband Noise
• - Develop a technique to actively control fan
  broadband noise

Source cross-correlation studies

• Advanced Fan Noise Reduction Concept
• - Design a 2-staged low tip speed fan with swept
  stator vanes and synchrophased fans to obtain
  active noise cancellation