Realistic Film Noise Generation Based on Experimental Noise Spectra

2020 ◽  
Vol 29 ◽  
pp. 2987-2998
Author(s):  
Sebastian Eckel ◽  
Peter Huthwaite ◽  
Uwe Zscherpel ◽  
Andreas Schumm ◽  
Nicolas Paul
1999 ◽  
Author(s):  
Christopher L. Banks ◽  
Sean F. Wu

Abstract This paper presents the results of an ongoing investigation of noise radiation from centrifugal blowers used in passenger vehicles. The semi-empirical formulation previously derived by the authors (1998) for predicting noise spectra of centrifugal blowers running in a free field is extended to centrifugal blowers installed in a HVAC scroll housing. Because of the presence of the scroll and cutoff, the flow fields are different from those in a free field. Accordingly, the noise generation mechanisms become much more difficult to analyze and model. The previous model assumed a monopole type sound radiation pattern, and predicted the broadband component of the noise spectra well. This model is extended to include the contributions of both monopole and directional dipole sound radiation. It is this complex radiation that is characteristic of a centrifugal blower situated inside a scroll housing with a cutoff. Comparisons of the calculated and measured noise spectra were demonstrated, and good agreements were obtained in all cases.


Author(s):  
Christopher K. W. Tam

This is a review of the two-source model of jet noise. The model was developed phenomenologically a number of years ago. One of the principal results associated with this model was the identification of two similarity jet noise spectra. This was accomplished through extensive comparisons with a large set of NASA spectrum data. It was found that these two noise spectra when combined appropriately would fit measured noise spectra of jets in any direction regardless of jet temperature and Mach number. Other experimental data in support of the two-source model have since been found. They are discussed in this paper. One of the purposes of this paper is to elaborate on the flow physics of turbulence, noise generation mechanisms and directivity that are the underpinnings of the model. More recent works show the similarity spectra are applicable, well beyond their original database, to noise of military jets, rockets and even volcanoes. This article is part of the theme issue ‘Frontiers of aeroacoustics research: theory, computation and experiment’.


2020 ◽  
Author(s):  
Kshitiz Kumar ◽  
Bo Ren ◽  
Yifan Gong ◽  
Jian Wu
Keyword(s):  

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