Numerical analysis of the acoustic field of reacting flows via acoustic perturbation equations

2008 ◽  
Vol 37 (9) ◽  
pp. 1157-1169 ◽  
Author(s):  
T.Ph. Bui ◽  
W. Schröder ◽  
M. Meinke
Keyword(s):  
Numerical Analysis ◽  
Acoustic Field ◽  
Reacting Flows ◽  
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.

Numerical analysis of the interaction between fluid flow and acoustic field at the mouth-opening of a flue instrument

2013 ◽  
Vol 133 (5) ◽  
pp. 3321-3321
Author(s):  
Takahiro Akamura ◽  
Yuki Nagao ◽  
Takuya Iwasaki ◽  
Ken'ichiro Nakano ◽  
Kin'ya Takahashi ◽  
...  
Keyword(s):  
Fluid Flow ◽  
Numerical Analysis ◽  
Acoustic Field ◽  
Mouth Opening

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

Numerical Analysis of the Acoustic Field of a Ducted Axial Fan at Varying Tip Clearances

2019 ◽  
Vol 105 (1) ◽  
pp. 43-55 ◽  
Author(s):  
S. M. Alavi Moghadam ◽  
M. Meinke ◽  
W. Schröder
Keyword(s):  
Numerical Analysis ◽  
Acoustic Field ◽  
Axial Fan

Numerical Analysis of a New-Style Ultrasonic Linear Array

2011 ◽  
Vol 58-60 ◽  
pp. 1043-1048
Author(s):  
Yong Wang ◽  
Quan Lu Li
Keyword(s):  
Numerical Analysis ◽  
Radiation Field ◽  
Acoustic Field ◽  
Linear Array ◽  
Acoustic Radiation ◽  
Acoustic Lens ◽  
Width Direction

In order to reduce the field of the acoustic radiation and improve the efficiency of energy using, a new-style ultrasonic linear array is present, which base on the special structural of the acoustic field produced by the cylindrical acoustic lens. The new-style linear array is composed of numbers of cylindrical acoustic lens, each lens act as an element distributed in a line along the width direction. Define x-direction is the direction of wave propagate. We have studied the acoustic field theoretically and have analyzed it numerically. Found that acoustic field have a better directivity in y-direction and the radiation field is much smaller than the traditional linear array, at the same time the focus ability is appear in the Z-direction if we control the number of element and the distance of center-to-center spacing of each element. This paper is helpful to the change and development of traditional liner array.

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