A New Computational Tool for Noise Prediction of Rotating Surfaces (FACT)

Authors: Ana Vieira, Fernando Lau, João Pedro Mortágua, Luís Cruz, Rui Santos

Abstract:

The air transport impact on environment is more than ever a limitative obstacle to the aeronautical industry continuous growth. Over the last decades, considerable effort has been carried out in order to obtain quieter aircraft solutions, whether by changing the original design or investigating more silent maneuvers. The noise propagated by rotating surfaces is one of the most important sources of annoyance, being present in most aerial vehicles. Bearing this is mind, CEIIA developed a new computational chain for noise prediction with in-house software tools to obtain solutions in relatively short time without using excessive computer resources. This work is based on the new acoustic tool, which aims to predict the rotor noise generated during steady and maneuvering flight, making use of the flexibility of the C language and the advantages of GPU programming in terms of velocity. The acoustic tool is based in the Formulation 1A of Farassat, capable of predicting two important types of noise: the loading and thickness noise. The present work describes the most important features of the acoustic tool, presenting its most relevant results and framework analyses for helicopters and UAV quadrotors.

Keywords: Rotor noise, acoustic tool, GPU Programming, UAV noise.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1099577

References:

[1] Ffowcs Williams J.E. and Hawkings D.L. Sound Generation by Turbulence and Surfaces in Arbitrary motion. Mathematical and Physical Sciences, 264(1151):321–342, May 1969.
[2] Farassat F. The Kirchhoff Formulas for Moving Surfaces in Aeroacoustics - The Subsonic and Supersonic Cases. Technical Memorandum 110285, NASA, Langley Research Center, Hampton, Virginia, September 1996.
[3] F. Farassat. Derivation of Formulation 1 and 1A Farassat. Technical report, NASA, March 2007.
[4] Br`es G.A., Brentner K.S., Perez G., and Jones H.E. Maneuvering rotorcraft noise prediction. Journal of Sound and Vibration, 275:719–738, 2004.
[5] Brentner K. S., Br`es G. A., G. Perez, and Jones H. E. Maneuvering Rotorcraft Noise Prediction: A New Code for a New Problem. Technical report, In Proceedings of AHS Aero- dynamics, Acoustics, and Test and Evaluation Technical Specialists Meeting, San Francisco, CA, January 2002.
[6] Ianniello S. Algorithm to Integrate the Ffowcs Williams-Hawkings Equation on Supersonic Rotating Domain. AIAA, 37(9):1040–1047, September 1999.
[7] Brentner K. S. and H.E. Jones. Noise Prediction For Maneuvering Rotorcraft. Technical report, NASA, 2000.
[8] Perez G., Brentner K. S., Br`es G. A., and Jones H. E. A First Step Toward the Prediction of Rotorcraft Maneuver Noise. Journal of the American Helicopter Society, 50(3):203–237, July 2005.
[9] Hsuan-nien C. Rotor noise in maneuvering flight. PhD thesis, The Pennsylvania State University, The Graduate School, December 2006.
[10] Brentner K. S., Burley C. L., and Marcolini M. A. Sensitivity of Acoustic Predictions to Variation of Input Parameters.