scholarly journals Ultrasonic Phased Array Techniques for Industrial Applications

2020 ◽  
Vol 69 (8) ◽  
pp. 569-574
Author(s):  
Tsuyoshi MIHARA

Micromachines ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 343 ◽  
Author(s):  
Koji Hasegawa ◽  
Ayumu Watanabe ◽  
Akiko Kaneko ◽  
Yutaka Abe

The contactless coalescence of a droplet is of paramount importance for physical and industrial applications. This paper describes a coalescence method to be used mid-air via acoustic levitation using an ultrasonic phased array system. Acoustic levitation using ultrasonic phased arrays provides promising lab-on-a-drop applications, such as transportation, coalescence, mixing, separation, evaporation, and extraction in a continuous operation. The mechanism of droplet coalescence in mid-air may be better understood by experimentally and numerically exploring the droplet dynamics immediately before the coalescence. In this study, water droplets were experimentally levitated, transported, and coalesced by controlled acoustic fields. We observed that the edges of droplets deformed and attracted each other immediately before the coalescence. Through image processing, the radii of curvature of the droplets were quantified and the pressure difference between the inside and outside a droplet was simulated to obtain the pressure and velocity information on the droplet’s surface. The results revealed that the sound pressure acting on the droplet clearly decreased before the impact of the droplets. This pressure on the droplets was quantitatively analyzed from the experimental data. Our experimental and numerical results provide deeper physical insights into contactless droplet manipulation for futuristic lab-on-a-drop applications.



2013 ◽  
Vol 134 (5) ◽  
pp. 4013-4013 ◽  
Author(s):  
Hossein Taheri ◽  
Fereidoon Delfanian ◽  
Jikai Du


2006 ◽  
Vol 110 ◽  
pp. 97-104 ◽  
Author(s):  
Sang Woo Choi ◽  
Joon Hyun Lee

The reactor vessel body and closure head are fastened with the stud bolt that is one of crucial parts for safety of the reactor vessels in nuclear power plants. It is reported that the stud bolt is often experienced by fatigue cracks initiated at threads. Stud bolts are inspected by the ultrasonic technique during the overhaul periodically for the prevention of failure which leads to radioactive leakage from the nuclear reactor. The conventional ultrasonic inspection for stud bolts was mainly conducted by reflected echo method based on shadow effect. However, in this technique, there were numerous spurious signals reflected from every oblique surfaces of the thread. In this study, ultrasonic phased array technique was applied to investigate detectability of flaws in stud bolts and characteristics of ultrasonic images corresponding to different scanning methods, that is, sector and linear scan. For this purpose, simplified stud bolt specimens with artificial defects of various depths were prepared.



2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Xufei Guo ◽  
Yan Han ◽  
Pengfei Nie

The ultrasonic phased array total focusing method (TFM) has the advantages of high imaging signal-to-noise ratio (SNR) and high defect resolution, but the problem of large amount data capturing and processing limits its practical industrial applications. To reduce the imaging calculation demand of the total focusing method, a half-matrix focusing method (HFM) is proposed based on the acoustic reciprocity. The method simplifies the calculation process of full-matrix data capturing (FMC) and total focus imaging. The experimental results show that the signal obtained by the linear array transceiver sensor is highly consistent, and the imaging resolution and signal-to-noise ratio of the half-matrix focusing method are slightly lower than those of full-matrix focusing method and higher than those of the B-scan imaging. However, compared with TFM, data acquisition and computational efficiency using the HFM have been improved significantly.





Author(s):  
Mike Troughton ◽  
Malcolm Spicer ◽  
Fredrik Hagglund

The current practice for assuring the quality of butt fusion joints in polyethylene (PE) pipes during installation is by recording the welding parameters used, together with a visual inspection of the welded joint, supplemented by the destructive testing of welds on a sample basis using a short-term test. However, visual inspection can only examine the external surface of the pipe weld; it cannot provide evidence of embedded flaws or a weld with incomplete fusion or cold fusion. In addition, cutting a specimen from a weld for mechanical testing and then replacing it with a weld of unknown quality does not ensure the integrity of the pipeline. Volumetric non-destructive examination (NDE) will not destroy perfectly good welds and has the added environmental advantage of reduced waste. This paper describes an ongoing European-funded project to develop ultrasonic phased array techniques for the inspection of butt fusion (BF) and electrofusion (EF) joints in PE pipes of diameters between 90 and 1000mm, and to determine critical defect sizes and particulate contamination levels using accelerated long-term testing. In addition, defect recognition and automated defect sentencing software will be developed to allow the system to automatically sentence detected flaws.



1993 ◽  
Vol 5 (2) ◽  
pp. 229-240
Author(s):  
Anton Erhard ◽  
Manzoor Hussain Khan ◽  
Liaquat Ali Rana


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