Near-field scanning in the time domain on a spherical surface - A formulation using the free-space Green's function

Date

2001-10-01

Author

Koc, S
Aydın Çivi, Hatice Özlem
Buyukdura, OM

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

198
views

0
downloads

Two formulations for determining the characteristics of an unknown source of acoustic waves using the measurement of its field at its near zone are presented. The measurement in both cases is to be performed on a spherical scan surface which encapsulates the source. The first is for an ideal probe which measures the field at its location. The knowledge of the field is sufficient; its normal derivative is not required. In the second formulation a realistic probe is considered. This time it is required only that the probe has an axially symmetric receiving characteristic. With this formulation, the time functions which characterize the source are found using only the signal at the output of the probe. Both formulations are such that they are not specific to the scan surface radius. Furthermore, they are entirely in the time domain, requiring no inverse Fourier transformations left to be performed. (C) 2001 Acoustical Society of America.

Subject Keywords

Acoustic waves

URI

https://hdl.handle.net/11511/39106

Journal

JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA

DOI

https://doi.org/10.1121/1.1403698

Collections

Department of Electrical and Electronics Engineering, Article

Suggestions

OpenMETU
Core

Response of acoustic imaging systems using convergent leaky waves to cylindrical flaws Günalp, Nilgün; Atalar, Abdullah (Institute of Electrical and Electronics Engineers (IEEE), 1989-9) A theoretical study of imaging systems utilizing focused leaky surface acoustic waves (SAWs), and their response to certain kind of defects is presented. In particular, circular cylindrical inhomogeneities with axes perpendicular to the surface are considered. The scattering of the SAW from this cylinder is formulated with some approximations. The surface wave incident on the inhomogeneity is initially found as an angular spectrum of plane waves. However, to apply the boundary conditions at the cylindrical ...
LONGITUDINAL ELASTIC-WAVE PROPAGATION AND ENERGY FLUX AT A DISCONTINUITY OF 2 DISSIMILAR SEMIINFINITE CIRCULAR RODS Yıldırım, Raif Orhan (1994-10-01) Elastic wave propagation through an area discontinuity of two dissimilar, bonded, semi-infinite circular rods is investigated analytically. In particular, the variations of the coefficients of stress reflection and transmission are determined in terms of the nondimensional cross sectional area and mechanical impedance parameters. The coefficients of energy flux reflection and transmission are also included. Then, the case is generalized to include a rigid mass attached at the discontinuity.
Standing wave acoustic levitation on an annular plate Kandemir, Mehmet Hakan; Çalışkan, Mehmet (2016-11-10) In standing wave acoustic levitation technique, a standing wave is formed between a source and a reflector. Particles can be attracted towards pressure nodes in standing waves owing to a spring action through which particles can be suspended in air. This operation can be performed on continuous structures as well as in several numbers of axes. In this study an annular acoustic levitation arrangement is introduced. Design features of the arrangement are discussed in detail. Bending modes of the annular plate...
Time-domain calculation of sound propagation in lined ducts with sheared flows Özyörük, Yusuf (1999-01-01) A recent application of the time-domain equivalent of the classical acoustic impedance condition, i.e. the particle displacement continuity equation, to the numerical simulations of a flow-impedance tube in the time domain yielded reasonably good results with uniform mean flows. The present paper extends this application to include sheared mean flow effects on sound propagation over acoustically treated walls. To assess the prediction improvements with sheared flows, especially at relatively high Mach numbe...
Design and implementation of an annular acoustic levitation system Kandemir, Mehmet Hakan; Çalışkan, Mehmet; Department of Mechanical Engineering (2014) In standing wave acoustic levitation technique, a standing wave is obtained between a source and a reflector. Particles can be attracted towards pressure nodes in standing waves owing to the spring action. Hence, particles can be suspended in air. This operation can be performed on continuous structures as well as in several numbers of axes. In this study an annular acoustic levitation set-up is designed and built. The set-up consists of two langevin type piezoelectric transducers, two waveguides, an annula...

Citation Formats

S. Koc, H. Ö. Aydın Çivi, and O. Buyukdura, “Near-field scanning in the time domain on a spherical surface - A formulation using the free-space Green’s function,” JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA, pp. 1778–1782, 2001, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/39106.