Broadband Noise Source Models as Aeroacoustic Tools in Designing Low NVH HVAC Ducts

2006 ◽  
Author(s):  
Omar M. Mohamud ◽  
Perry Johnson
Keyword(s):  
Noise Source ◽  
Broadband Noise ◽  
Source Models

Prediction of the Aerodynamic Acoustic Power Contribution on Automobile’s Surface Based on Curle’s Integral in Broadband Noise Source Models

2011 ◽  
Vol 317-319 ◽  
pp. 2284-2288
Author(s):  
Zhen Gyu Zheng ◽  
Ren Xian Li
Keyword(s):  
High Speed ◽  
Optimization Design ◽  
Noise Source ◽  
Power Level ◽  
Research Work ◽  
Acoustic Power ◽  
Broadband Noise ◽  
Vehicle Body ◽  
Aerodynamic Noise ◽  
Source Models

The Aerodynamic noise, which is generated by the moving vehicle at high speed, is a kind of broadband noise. This paper dwelled on the Ligthill’s Acoustic Analogy firstly, and applied the realizable k-ε turbulence model to simulate the external steady flow field of automobile, so as to get the distribution characters of statistical turbulence quantities based on the Reynolds-averaged Navier-Stokes (RANS) equation. Then the Curle’s Integral in Broadband Noise Source Models was utilized to predict the local aerodynamic acoustic power contribution on automobile’s surface, which is helpful to the farther research work in the vehicle body optimization design based on aerodynamic noise controlling. The results shows that: The aerodynamic acoustic power contribution regions on surface mainly distribute near the automobile’s head and tail; and the maximum SAPL (Surface Acoustic Power Level) value is up to 83.15 dB in the vicinity of the rear wheel hub when the vehicle speed is 120km/h; the higher the speed of automobile, the more scattered the distribution of main aerodynamic acoustic power on automobile’s surface.

On Predicting Aeroacoustic Performance of Ducts with Broadband Noise Source Models

2005 ◽  
Author(s):  
Ashok D. Khondge ◽  
Sandeep D. Sovani ◽  
Sung-Eun Kim ◽  
Steven C. Guzy ◽  
Ashraf A. Farag
Keyword(s):  
Noise Source ◽  
Broadband Noise ◽  
Source Models

Physics-informed Broadband Noise Source Identification and Prediction of an Ideally Twisted Rotor

2021 ◽  
Author(s):  
Christopher Thurman ◽  
Nikolas S. Zawodny ◽  
Nicole A. Pettingill ◽  
Leonard V. Lopes ◽  
James D. Baeder
Keyword(s):  
Source Identification ◽  
Noise Source ◽  
Broadband Noise ◽  
Noise Source Identification

Design of a 0.1~18GHz High-Power Broadband Noise Source

2020 ◽  
Author(s):  
Rikang Zhao ◽  
Tingming Yao ◽  
Xidong Duan ◽  
Guoqing Fan ◽  
Shoumei Cheng ◽  
...  
Keyword(s):  
High Power ◽  
Noise Source ◽  
Broadband Noise

Numerical Analysis of the Surface Aerodynamic Noise of the CRH3 High Speed Train

2014 ◽  
Vol 1044-1045 ◽  
pp. 643-649
Author(s):  
Ji Zhou Liu ◽  
Ren Xian Li ◽  
Peng Xiang Cui
Keyword(s):  
High Speed ◽  
Noise Source ◽  
Radiation Power ◽  
Spectral Characteristics ◽  
Radiation Energy ◽  
Simulation Method ◽  
Acoustic Power ◽  
Broadband Noise ◽  
Aerodynamic Noise ◽  
High Speed Train

For high speed trains running at 300km/h or more, the aerodynamic noise becomes the primary noise source. A good knowledge of the location, spectral characteristics and propagation behavior of the noise source and the corresponding methods to reduce the effect of the aerodynamic noise are of crucial necessity during the design process of the high speed train. Based on the Lighthill Analogy, the pressure fluctuation of air at the surface of the train is acquired by simulating the flow field of a CRH3 high speed train running at 200 km/h, 300 km/h, 400 km/h and 500km/h by means of large eddy simulation method. By Fourier transformation, the distribution and the spectral characteristics of the surface acoustic dipole sources are obtained. The analysis of the results shows that the aerodynamic noise of the high speed train is a broadband noise with a strong radiation power band from 50Hz to 1000Hz. The dipole acoustic power calculated by statistically averaged on train surface is found to be proportional to the sixth power of running speed of the high speed train. The first and second bogie, the inter-car gap, the air deflector of the power train and the train nose of the last wagon are the main noise sources that contain high radiation energy.

Noise source models for fricative consonants

2000 ◽  
Vol 8 (3) ◽  
pp. 328-344 ◽  
Author(s):  
S. Narayanan ◽  
A. Alwan
Keyword(s):  
Noise Source ◽  
Source Models
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