Structural Design to Maximum Radiating Power of Langevin Bolted Ultrasonic Transducer
Pak Myong-Il,
Ri Ui-Hwan,
An Yong-Nam
Issue:
Volume 1, Issue 2, December 2017
Pages:
40-45
Received:
28 November 2016
Accepted:
30 March 2017
Published:
5 May 2017
DOI:
10.11648/j.ep.20170102.12
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Abstract: Langevin bolted transducers (BLT) with two piezoelectric ceramics inserted between the front and rear plates are widely used in ultrasonic cleaner transducers and components of underwater acoustic antennas for a fish finder [1, 2]. And it is very important to attain a maximum ratio of vibrating velocities of the front and rear plates of transducers in radiating medium by choosing the optimal dimension of the front and rear plates of ultrasonic transducers. Prior studies introduced the vibrating mode analysis of BLT using FEM analysis and ultrasonic applications [3, 4, 5]. But study about the detailed structural design of transducers with the maximum vibrating velocity ratio of the front and back plates in the radiating medium based on the electromechanical equivalent circuit analysis is hardly found. In this paper we identified the optimal geometrical dimension of the front and rear plates of transducers with maximum vibrating velocity ratio for 20kHz of working frequency and applied FEM analysis using the ANSYS software. These are based on the analysis of 1-D longitudinal vibrating equivalent circuit for BLT inserted two piezoceramics between the front and rear plates. The front plate is conical shaped and rear plate is cylindrical shaped and these are consisted of different materials.
Abstract: Langevin bolted transducers (BLT) with two piezoelectric ceramics inserted between the front and rear plates are widely used in ultrasonic cleaner transducers and components of underwater acoustic antennas for a fish finder [1, 2]. And it is very important to attain a maximum ratio of vibrating velocities of the front and rear plates of transducers...
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Effect of Some Additions on the Structure and Mechanical Properties of A356 - Al Si Alloy
A. M. Ahmed Ali,
A. G. Mostafa,
A. N. Abdalazim,
A. A. Ramadan,
I. S. Ahmed Farag
Issue:
Volume 1, Issue 2, December 2017
Pages:
46-51
Received:
7 June 2017
Accepted:
22 June 2017
Published:
27 July 2017
DOI:
10.11648/j.ep.20170102.13
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Abstract: The modified eutectic silicon or refinement of primary silicon particles with uniform distribution are desired in real casting practice. In order to modify the microstructure of Al-Si alloys, many techniques are available. However the deliberate additions of several elements during melting are still the most easy and efficient way than other different techniques. Trace addition of Na or Sr is commonly used to modify the eutectic structure of Al-Si alloys from coarse plate-like structure in unmodified alloys to fine fibrous morphology in modified ones. Such a fine structure can potentially increase the ductility and tensile properties of these alloys. It was concluded that, 7% Si – 0.3% Mg alloys appeared to be a good refiner when treated by the additions of 0.2-0.4% AlTiB master alloy. In the same time, this alloy reaches good modification by the addition of 0.2-0.4 wt % of Al-10% Sr. The obtained results were compared with those obtained by using the traditional well known AlSr master alloy, AlTiB and a mixture of both AlTiB and AlSr.
Abstract: The modified eutectic silicon or refinement of primary silicon particles with uniform distribution are desired in real casting practice. In order to modify the microstructure of Al-Si alloys, many techniques are available. However the deliberate additions of several elements during melting are still the most easy and efficient way than other differ...
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for the Fresnel-Kirchoff diffraction parameter; 
for the radius of the Fresnel zone and 
for the number of Fresnel zones that are blocked by obstruction in the signal path. Consequently, if the value of any of the three parameters is known at frequency, f1, then the corresponding value of the same parameter at another frequency, f2 can be obtained by multiplying the parameter value at f1 with the frequency scaling factor for the parameter.