On the prediction of far-field fan noise attenuation due to liners considering uniform and shear flows

2018 ◽  
Author(s):  
Danilo S. Braga ◽  
Andre Spillere ◽  
Julio A. Cordioli ◽  
Andrey R. da Silva ◽  
Danillo C. Reis
Keyword(s):  
Shear Flows ◽  
Far Field ◽  
Noise Attenuation ◽  
Fan Noise

Intake Fan Noise Attenuation due to Liners Considering Uniform and Shear Flows

AIAA Journal ◽  
2019 ◽  
Vol 57 (8) ◽  
pp. 3480-3492
Author(s):  
Danilo de S. Braga ◽  
André M. N. Spillere ◽  
Andrey R. Da Silva ◽  
Júlio A. Cordioli ◽  
Danillo C. Reis
Keyword(s):  
Shear Flows ◽  
Noise Attenuation ◽  
Fan Noise

Noise Characteristics of Automobile Cooling Fan Based on Circumferential Mode Analysis

2021 ◽  
Author(s):  
Pengfei Chai ◽  
Zonghan Sun ◽  
Zhiqiang Chang ◽  
Zhigang Peng ◽  
Jie Tian ◽  
...  
Keyword(s):  
Automobile Industry ◽  
Cooling System ◽  
Tip Clearance ◽  
Mode Analysis ◽  
Far Field ◽  
Axial Fan ◽  
Fan Noise ◽  
Cooling Fan ◽  
Noise Characteristics ◽  
Cooling Fans

Abstract The fan is the main component of the cooling system of an automobile engine. A typical automobile cooling fan consists of a shrouded axial fan, stator vanes, a deflector, and a cover. With recent developments in the automobile industry, the increase in the speed of rotation and blade load of cooling fans has increased the noise generated by them. To reduce it, it is important to analyze the characteristics of this noise. This paper uses an acoustic test to examine the characteristics of flow and noise of automobile cooling fans. The frequency spectrum and far-field radiation of the noise of the fan are first analyzed through far-field measurements, and the influence of the single rotor, tip clearance of the blade, and cover on fan noise is studied. The distribution of the mode spectrum and characteristics of sound propagation of discrete tonal noise are then examined using the circumferential mode test. The influence of the flow structure on fan noise is also studied. The flow characteristics and distribution of the source of noise of the automobile cooling fan are then used to analyze the influence of the structure of the fan on the noise generated by it. The results can help develop designs to reduce the noise of automobile cooling fans.

Noise Characteristics of Automobile Cooling Fan Based On Circumferential Mode Analysis

2021 ◽  
Author(s):  
Pengfei Chai ◽  
Zonghan Sun ◽  
Zhiqiang Chang ◽  
Zhigang Peng ◽  
Jie Tian ◽  
...  
Keyword(s):  
Automobile Industry ◽  
Cooling System ◽  
Tip Clearance ◽  
Mode Analysis ◽  
Far Field ◽  
Axial Fan ◽  
Fan Noise ◽  
Cooling Fan ◽  
Noise Characteristics ◽  
Cooling Fans

Abstract The fan is the main component of the cooling system of an automobile engine. A typical automobile cooling fan consists of a shrouded axial fan, stator vanes, a deflector, and a cover. With recent developments in the automobile industry, the increase in the speed of rotation and blade load of cooling fans has increased the noise generated by them. To reduce it, it is important to analyze the characteristics of this noise. This paper uses an acoustic test to examine the characteristics of flow and noise of automobile cooling fans. The frequency spectrum and far-field radiation of the noise of the fan are first analyzed through far-field measurements, and the influence of the single rotor, tip clearance of the blade, and cover on fan noise is studied. The distribution of the mode spectrum and characteristics of sound propagation of discrete tonal noise are then examined using the circumferential mode test. The influence of the flow structure on fan noise is also studied. The flow characteristics and distribution of the source of noise of the automobile cooling fan are then used to analyze the influence of the structure of the fan on the noise generated by it. The results can help develop designs to reduce the noise of automobile cooling fans.

Far-field measurement and mode analysis of the effects of vane/bladeratio on fan noise

1984 ◽  
Author(s):  
P. SCHWALLER ◽  
A. PARRY ◽  
M. OLIVER ◽  
A. ECCLESTON
Keyword(s):  
Field Measurement ◽  
Mode Analysis ◽  
Far Field ◽  
Fan Noise

Fan Noise Source Diagnostic Test -- Far-field Acoustic Results

2002 ◽  
Author(s):  
Richard Woodward ◽  
Christopher Hughes ◽  
Robert Jeracki ◽  
Christopher Miller
Keyword(s):  
Diagnostic Test ◽  
Noise Source ◽  
Far Field ◽  
Fan Noise

The Attenuation Trend of the Propeller Noise

2013 ◽  
Vol 774-776 ◽  
pp. 82-85
Author(s):  
Chang Run Xiao ◽  
Rui Jie Liu ◽  
Jin Ming Ye
Keyword(s):  
Time Domain ◽  
Near Field ◽  
Dipole Source ◽  
Frequency Noise ◽  
Far Field ◽  
Noise Attenuation ◽  
Blade Surface ◽  
Propeller Noise ◽  
Unsteady Loading ◽  
Blade Frequency

The blade frequency noise of non-cavitation propellers in an non-uniform flow is analyzed in time domain. The unsteady loading (dipole source) on the blade surface is calculated by a potential-based panel method. Through calculation and comparison, the noise attenuation trend of propeller is discussed. The noise decays more quickly in the near field than in the far field. The Attenuation Trend of the Propeller Noise

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

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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