The Aeroacoustics Branch located at the NASA Langley Research Center (LaRC), is one branch within the NASA Langley Research Directorate. The Aeroacoustics Branch plans and conducts research aimed at understanding and accurately predicting the noise from any air vehicle configuration as well as defining and demonstrating concepts for air vehicle noise reduction. The scope of this research is broad and includes fundamental, theoretical, analytical, experimental, and applied research in aeroacoustics. The Aeroacoustics Branch directly supports projects within the Advanced Air Vehicles Program, Integrated Aviation Systems Program, and the Transformative Aeronautics Concepts Program of the NASA Aeronautics Research Mission Directorate. These projects are:
- Advanced Air Transport Technology
- Commercial Supersonic Technology
- Revolutionary Vertical Lift Technology
- Flight Demonstrations and Capabilities
- Convergent Aeronautics Solutions
- Transformational Tools and Technologies
Research emphasis includes the fluid mechanics and acoustics of various aircraft components such as high lift devices, landing gear, rotors, propellers/open rotors, and nacelles/liners. The interactions of various components, particularly propulsion airframe aeroacoustic effects (jet with airframe or propeller/rotor with airframe) including acoustic scattering/shielding, and atmospheric sound propagation are additional important areas of study. These activities lead to system level aircraft noise understanding, assessment, prediction, and auralization research efforts within the branch.
Objectives of the research are to understand aeroacoustic noise generation processes, to develop methods for predicting acoustics and flow fields and their interactions, and to identify and demonstrate noise reduction and control techniques. Experimental research is conducted in laboratories, in anechoic facilities, in wind tunnels, and on vehicles in flight. Current code development is based on Computational Fluid Dynamics in conjunction with the Lighthill acoustic analogy. The new multi-fidelity Aircraft Noise Prediction Program (ANOPP2) provides a framework that includes the workhorse ANOPP and its latest updates, as well as capability to utilize high-fidelity, physics-based tools. The NASA Auralization Framework (NAF) auralizes sounds from known source data allowing for perception influenced design. The Aeroacoustics Branch uses a number of unique facilities to accomplish this research.