Fan Noise Source Diagnostic Test - Tone Modal Structure Results

Data taken in the Source Diagnostic Test of the unsteady pressure on a fan-exit guide vane is analyzed to identify the dominant noise producing regions on the vane. The dominant noise source regions of the vane are identified as the outer fifty percent span of the vane. The sensitivity of this result to fan tip speed and exit guide vane sweep is studied. Sweep is seen to decrease the radial correlation length of the unsteady vane response and hence decrease the noise produced by wake-vane interaction. Results for the periodic component of the fan wakes show that the magnitude of the wake harmonics is largest in the outer fifty percent span of the duct and the radial phase variation is largest in the hub region. These results demonstrate a strong cause and effect relationship between the radial distribution of the wake harmonics and the dominant noise producing regions on the fan-exit guide vane.

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Fan noise source location from field measurements

10.2514/6.1980-1054 ◽

1980 ◽

Author(s):

A. CARGILL

Keyword(s):

Noise Source ◽

Field Measurements ◽

Source Location ◽

Fan Noise

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K-1246 Fan Noise Source Prediction Using Three-dimensional CFD Stage Analysis

The proceedings of the JSME annual meeting ◽

10.1299/jsmemecjo.v.01.1.0_173 ◽

2001 ◽

Vol V.01.1 (0) ◽

pp. 173-174

Author(s):

Naoki TSUCHIYA ◽

Masaru UNNO ◽

Yoshiya NAKAMURA ◽

Hidekazu KODAMA ◽

Osamu NOZAKI ◽

...

Keyword(s):

Noise Source ◽

Three Dimensional ◽

Fan Noise ◽

Stage Analysis

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Integrated “CFD - Acoustic” Computational Approach to the Simulation of Aircraft Fan Noise

Volume 2A: Turbomachinery ◽

10.1115/gt2014-26429 ◽

2014 ◽

Author(s):

Piergiorgio Ferrante ◽

Paolo di Francescantonio ◽

Pierre-Alain Hoffer ◽

Stéphane Vilmin ◽

Charles Hirsch

Keyword(s):

Unsteady Flow ◽

Sound Propagation ◽

Noise Source ◽

Acoustic Radiation ◽

Near Field ◽

Sound Field ◽

Computational Approach ◽

Far Field ◽

Fan Noise ◽

Field Noise

An innovative computational approach, integrating mesh generation, CFD simultaneous analysis of noise source and propagation, with acoustic radiation, is presented and applied to the simulation of the Advanced Noise Control Fan (ANCF) developed by NASA Glenn Research Center. The tonal noise source and the sound propagation in the nacelle duct and in the nacelle near field are simultaneously predicted, starting from the engine geometry and parameters, with a single CFD analysis based on an efficient Nonlinear Harmonic (NLH) method. The sound radiation to the far field is computed with the Green’s function approach implemented in a BEM frequency domain solver of the convective Helmholtz equation. The present method provides to a gain of close to two orders of magnitude compared to standard approaches, based on full unsteady flow simulations, followed by a near-field FEM based approach and a BEM method for the far-field noise propagation. The final comparison between the numerical results and the measurements highlights the capability of the methodology to efficiently predict the unsteady flow field and the radiated sound field.

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