0
Research Papers

Equivalent Source Method-Based Nearfield Acoustic Holography in a Moving Medium

[+] Author and Article Information
Chuan-Xing Bi

Institute of Sound and Vibration Research,
Hefei University of Technology,
193 Tunxi Road,
Hefei 230009, China
e-mail: cxbi@hfut.edu.cn

Bi-Chun Dong

Institute of Sound and Vibration Research,
Hefei University of Technology,
193 Tunxi Road,
Hefei 230009, China
e-mail: dongbchabc@163.com

Xiao-Zheng Zhang

Institute of Sound and Vibration Research,
Hefei University of Technology,
193 Tunxi Road,
Hefei 230009, China
e-mail: xzhengzhang@hfut.edu.cn

Yong-Bin Zhang

Institute of Sound and Vibration Research,
Hefei University of Technology,
193 Tunxi Road,
Hefei 230009, China
e-mail: ybzhang@hfut.edu.cn

1Corresponding author.

Contributed by the Noise Control and Acoustics Division of ASME for publication in the JOURNAL OF VIBRATION AND ACOUSTICS. Manuscript received December 22, 2016; final manuscript received February 28, 2017; published online July 13, 2017. Assoc. Editor: Miao Yu.

J. Vib. Acoust 139(5), 051017 (Jul 13, 2017) (8 pages) Paper No: VIB-16-1606; doi: 10.1115/1.4036498 History: Received December 22, 2016; Revised February 28, 2017

To identify sound sources situated in a fluid flow, an equivalent source method (ESM)-based nearfield acoustic holography (NAH) in a moving medium is proposed, and two types of acoustic inputs, pressure and particle velocity, are considered. In particular, an analytical relationship between the particle velocity perpendicular to the flow direction and the equivalent source strength is deduced, which makes it possible to realize the reconstruction with particle velocity input. Compared to the planar NAH in a moving medium, the proposed method is applicable to sound sources with more complicated geometries. Numerical simulations with sound sources distributed over two types of geometries including planar geometry and nonplanar one are conducted to test the performances of the proposed method. The results indicate that the proposed method provides satisfactory reconstructed results whatever with pressure input or with particle velocity input, and it is valid and robust over a wide range of flow velocities and frequencies and under different levels of background noise.

FIGURES IN THIS ARTICLE
<>
Copyright © 2017 by ASME
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Fig. 1

Geometry of ESM-based NAH in a moving medium

Grahic Jump Location
Fig. 2

The pressures on the reconstruction plane: the theoretical pressure (a), the reconstructed pressure by ESM-based NAH in a moving medium with pressure input (b), and the reconstructed pressure by ESM-based NAH in a moving medium with particle velocity input (c)

Grahic Jump Location
Fig. 3

The pressures on the reconstruction plane: the reconstructed pressure by planar NAH in a moving medium with pressure input (a) and the reconstructed pressure by planar NAH in a moving medium with particle velocity input (b)

Grahic Jump Location
Fig. 4

Reconstruction errors at different flow velocities provided by the ESM-based NAH in a moving medium (MESM) with pressure input (solid line) and with particle velocity input (dashed line) and by conventional ESM-based NAH (CESM) with pressure input (dotted line) and with particle velocity input (dashed–dotted line)

Grahic Jump Location
Fig. 5

Reconstruction errors at different frequencies provided by ESM-based NAH in a moving medium with pressure input (solid line) and with particle velocity input (dashed line) when M = 0.3

Grahic Jump Location
Fig. 6

Reconstruction errors for different SNRs provided by ESM-based NAH in a moving medium with pressure input (solid line) and with particle velocity input (dashed line) when M = 0.3

Grahic Jump Location
Fig. 7

Layout of the monopoles (a) and layout of the measurement points, the reconstruction points, and the equivalent sources (b) on the cross section y–o–z plane

Grahic Jump Location
Fig. 8

The pressures on the reconstruction surface: the theoretical pressure (a), the reconstructed pressure by ESM-based NAH in a moving medium with pressure input (b), and the reconstructed pressure by ESM-based NAH in a moving medium with particle velocity input (c)

Grahic Jump Location
Fig. 9

Reconstruction errors at different flow velocities provided by the ESM-based NAH in a moving medium (MESM) with pressure input (solid line) and with particle velocity input (dashed line) and by conventional ESM-based NAH (CESM) with pressure input (dotted line) and with particle velocity input (dashed–dotted line)

Grahic Jump Location
Fig. 10

Reconstruction errors at different frequencies obtained by ESM-based NAH in a moving medium with pressure input (solid line) and with particle velocity input (dashed line) when M = 0.3

Grahic Jump Location
Fig. 11

Reconstruction errors for different SNRs provided by ESM-based NAH in a moving medium with pressure input (solid line) and with particle velocity input (dashed line) when M = 0.3

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In