FUNDAMENTAL NOISE

NASA GLENN RESEARCH CENTER

Loretta Shaw, Subsonic Systems OfficeDennis Huff, Acoustic Branch Chief

Propulsion Systems Program

Aerospace Propulsion and Power Base Program

Objective: Develop advanced concepts to reduce subsonic engine fan, jet and core noise.

Fundamental Noise

Propulsion Fundamentals Research Project

Objective: …to provide support for new high-risk, high-payoffactivities that are of long term strategic importance

Propulsion Systems Program

Aeroacoustic Propulsion Laboratory

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

Aerospace Propulsion and Power Base Program

Propulsion Systems Program

Fundamental Noise Approach in FY00

Small Hot Acoustic Jet Rig

• Fan Noise Prediction- Develop the next generation fan noise prediction tools

based on Computational Aeroacoustics

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

MGBKprediction

Data

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

Aerospace Propulsion and Power Base Program

Propulsion Systems Program

Fundamental Noise Approach in FY00 Continued

ï 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

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

Source cross-correlation studies