A Software Tool for Improved Noise Source Identification and Understanding

Innovative Technology Applications Company and Drs. P. Morris and K. Brentner will make improvements in noise prediction and measurement methods for subsonic and supersonic vehicles. Possible areas of application for the finished product include aerodynamic noise from fans, jets, turbomachinery, engine cores, propfans, propellers, and airframe components. The proposed Phase I work will result in a proof-of-concept demonstration of a tool which will enable the NASA customer to gain deeper insight into aerodynamic noise sources and develop improved methods for experimentally detecting them. Ultimately, this will enable improved source identification techniques and greater understanding of the physics associated with the data obtained from experimental phased array microphone arrays. The approach taken by the proposed work to accomplish these goals is to use an unsteady simulation of nearfield unsteady flow to feed a Ffowcs Williams-Hawking solver. The acoustic field is then propagated to a numerical phased array of microphones and the data recorded just as it would in a wind tunnel or flyover experiment. The data is then processed according to the state-of-the-art data reduction methods and the resulting predictions of noise sources compared to the detailed data from the unsteady simulation to gain additional insight.