| ABSTRACT: | DECENTERED ANNULAR TRANSDUCER ARRAY FOR GENERATING DIRECTION-
VARIABLE ACOUSTIC BEAM
H. Masuyama1, K.Mizutani2, and K. Nagai2
1Toba National College of Maritime Technology; Toba, Japan; 2University of Tsukuba, Tsukuba, Japan
In this paper, we propose a method for generating a direction-variable acoustic wave beam with sharp profile
using a decentered annular transducer
array.
Imaging equipment using acoustic wave is one of the important technology in nondestructive testing,
because of features such as noninvasiveness, ease of handling, and so on.
In order to obtain a result with a high transverse resolution, it is necessary to use an acoustic beam of which
the width is narrow.
Bessel Beam is one of the solutions, and we proposed a method for approximately generating acoustic
Bessel Beam with a sound source by a concentric annular transducer array, which has the simple structure.
The source has the clearance between each neighboring element of the array, so applying these clearances to
decenter the array elements, it becomes possible that the direction of radiated beam is made to change.
The results of numerical calculations using this method show that the beam radiated to the direction of a
maximum of 15 degrees from the perpendicular of the source plane keeps the sharp profile, and the validity
of this method is verified.
The sound source fabricated by this method has the small, simple and planar structure, so the source has
advantages such as high flexibility of installing place and simplicity of manipulation.
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