NASA Technical Reports Server (NTRS) : Fan pdf

NASA Technical Reports Server (NTRS) : Fan

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Description of the Book:

An important source mechanism of fan broadband noise is the interaction of rotor wake turbulence with the fan outlet guide vanes. A broadband noise model that utilizes computed rotor flow turbulence from a RANS code is used to predict fan broadband noise spectra. The noise model is employed to examine the broadband noise characteristics of the 22-inch Source Diagnostic Test fan rig for which broadband noise data were obtained in wind tunnel tests at the NASA Glenn Research Center. A 9-case matrix of three outlet guide vane configurations at three representative fan tip speeds are considered. For all cases inlet and exhaust acoustic power spectra are computed and compared with the measured spectra where possible. In general, the acoustic power levels and shape of the predicted spectra are in good agreement with the measured data. The predicted spectra show the experimentally observed trends with fan tip speed, vane count, and vane sweep.

The results also demonstrate the validity of using CFD-based turbulence information for fan broadband noise calculations

• Creator/s: NASA Technical Reports Server (NTRS
• Date: 8/1/2002
• Year: 2002
• Book Topics/Themes: NASA Technical Reports Server (NTRS), FAN BLADES, TURBULENCE, WAKES, ROTORS, ROTOR AERODYNAMICS, NOISE MEASUREMENT, GUIDE VANES, AERODYNAMIC NOISE, WIND TUNNEL TESTS, NOISE SPECTRA, BROADBAND, TIP SPEED, MODELS, POWER SPECTRA, COMPUTATIONAL FLUID DYNAMICS, Nallasamy, M., Envia, E., Thorp, S. A., Shabbir, A

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