Acoustic perturbation equations and Lighthill’s acoustic analogy for the human phonation

2013 ◽  
Vol 133 (5) ◽  
pp. 3618-3618 ◽  
Author(s):  
Stefan Zoerner ◽  
Petr Šidlof ◽  
Andreas Hüppe ◽  
Manfred Kaltenbacher
Keyword(s):  
Acoustic Analogy ◽  
Acoustic Perturbation ◽  
Perturbation Equations

scholarly journals Acoustic perturbation equations and Lighthill's acoustic analogy for the human phonation

2013 ◽  
Author(s):  
Stefan Zoerner ◽  
Petr Sidlof ◽  
Andreas Hüppe ◽  
Manfred Kaltenbacher
Keyword(s):  
Acoustic Analogy ◽  
Acoustic Perturbation ◽  
Perturbation Equations

scholarly journals Prediction of flow-control devices' noise with modified acoustic perturbation equations

2020 ◽  
Vol 22 (3) ◽  
pp. 619-627
Author(s):  
Luca Fenini ◽  
Stefano Malavasi
Keyword(s):  
Flow Control ◽  
Fluid Dynamic ◽  
International Standards ◽  
The Other ◽  
Computational Time ◽  
Noise Prediction ◽  
Acoustic Perturbation ◽  
Flow Control Devices ◽  
Control Devices ◽  
Perturbation Equations

Abstract Fluid-dynamic noise emissions produced by flow-control devices inside ducts are a concerning issue for valve manufacturers and pipeline management. This work proposes a modified formulation of Acoustic Perturbation Equations (APE) that is applicable to industrial frameworks where the interest is addressed to noise prediction according to international standards. This formulation is derived from a literature APE system removing two terms allowing for a computational time reduction of about 20%. The physical contribution of the removed terms is discussed according to the literature. The modified APE are applied to the prediction of the noise emitted by an orifice. The reliability of the new APE system is evaluated by comparing the Sound Pressure Level (SPL) and the acoustic pressure with the ones returned by LES and literature APE. The new formulation agrees with the other methods far from the orifice: moving over nine diameters downstream of the trailing edge, the SPL is in accordance with the other models. Since international standards characterize control devices with the noise measured 1 m downstream of them, the modified APE formulation provides reliable and faster noise prediction for those devices with outlet diameter, d, such that 9d < 1 m.

scholarly journals SPECTRAL FINITE ELEMENTS FOR COMPUTATIONAL AEROACOUSTICS USING ACOUSTIC PERTURBATION EQUATIONS

2012 ◽  
Vol 20 (02) ◽  
pp. 1240005 ◽  
Author(s):  
ANDREAS HÜPPE ◽  
MANFRED KALTENBACHER
Keyword(s):  
Finite Element ◽  
Mixed Finite Element ◽  
Finite Element Approximation ◽  
Computational Aeroacoustics ◽  
Element Approximation ◽  
Mean Flow ◽  
Fe Method ◽  
Acoustic Perturbation ◽  
The Impact ◽  
Perturbation Equations

This paper addresses the application of the spectral finite element (FE) method to problems in the field of computational aeroacoustics (CAA). We apply a mixed finite element approximation to the acoustic perturbation equations, in which the flow induced sound is modeled by assessing the impact of a mean flow field on the acoustic wave propagation. We show the properties of the approximation by numerical benchmarks and an application to the CAA problem of sound generated by an airfoil.

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