scholarly journals Analysis of the influence of vertical sound field distribution on acoustic testing in shallow sea environment

Author(s):  
Xiaofeng Wang ◽  
Zhaoran Meng ◽  
Bo Liu
Author(s):  
Bing Wang ◽  
Yadong Wang ◽  
Wenjun Liang ◽  
Shuiping Sheng ◽  
Jianping Guo ◽  
...  

Recently, acoustic testing method has been widely used for valve leakage inspection. Traditional method has difficulty carrying out research on the acoustic testing of valve leakage due to the complex geometry of the valve and the effect of flow on sound field. Thus, a numerical method was put forward based on Reynolds average N-S equation and k – ε equation in order to investigate the flow of the inner leakage of ball valve, needle valve and gate valve. Furthermore, difference time domain method was adopted to simulate the noise field of the flow based on Lighthill acoustic equation. And the characteristics of acoustic distribution were obtained. The results showed that turbulent flow was the main cause of jet noise inner the valve due to gas leakage. And the acoustic distribution had directivity. There were about 10 ∼ 25dB difference between the upstream and downstream of the leaking valve. The position with the highest sound pressure was also found out.


2002 ◽  
Vol 48 (3) ◽  
pp. 263-267 ◽  
Author(s):  
N. K. Vdovicheva ◽  
A. L. Matveev ◽  
A. G. Sazontov

2012 ◽  
Vol 466-467 ◽  
pp. 523-527
Author(s):  
Qi Zhang ◽  
Rong Bao Chen ◽  
Xuan Yu Li ◽  
Chang Hua Chen

Compared to the probe based on conventional piezoelectric ceramic, the high-performance ultrasonic probe made from polymer composite materials is much better, which has characteristics such as high sensitivity, wide bandwidth and good directional. And probe’s thickness electromechanical coupling coefficient KT value is up to 68%, which means it can reduce the crosstalk effectively to the phased array probe. In industrial, due to its high bandwidth, it has obvious advantages when used in coarse-grained materials testing and high-precision thickness measurement. In the medical field, ultrasound will reflex significantly at the impurities or the interfaces, and produce the Doppler effect in the flow of blood. Based on the sound field distribution comparative study of polymer materials ultrasonic probe chip, this paper proposed some polymer new applications in ultrasonic testing field.


2013 ◽  
Vol 716 ◽  
pp. 559-564
Author(s):  
Di Jia ◽  
Feng Hui Kang ◽  
Yi Na Wang

In order to study the acoustic environment of a ship sonar platform, near-field acoustic characteristic of a compound structure with plates & a cylindrical shell (CSPCS) subjected to sound excitation is researched based on numerical simulation. Influence of frequency and sound incident angle on acoustic environment of CSPCS are studied. Study shows that the sound pressure field distribution of CSPCS is complicated. Sound pressure would be strengthened and weakened in different locations when sound pressure uniformly incident into CSPCS. Result shows that the sound pressure distribution is highly dependent on frequency and incident angle. Sound pressure field is more evenly distributed when sound wave frequency is low. Study also shows that the incident angle has considerable influence on the sound field distribution of strengthened and weakened area.


2018 ◽  
Vol 8 (2) ◽  
pp. 157 ◽  
Author(s):  
Yury Morgunov ◽  
Aleksandr Golov ◽  
Aleksandr Burenin ◽  
Peter Unru ◽  
Aleksandr Rodionov ◽  
...  

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