Development and Improvement of the Experimental Apparatus Using the Underwater Shock Wave

2013 ◽  
Vol 767 ◽  
pp. 256-260
Author(s):  
Yukimasa Omine ◽  
Takashi Gushi ◽  
Osamu Higa ◽  
Shigeru Itoh

The underwater shock wave has been studied in the various fields. The application of this method can be used for a molding machining, a welding and an embossing in the metal processing [. Moreover, this processing method can be used for a pulverizing, a softening, and a sterilization in the food processing. The aim of this research is to make the rice powder using by the underwater shock wave without generating of heat [. Although the underwater shock wave is generated using an explosive, the handling of the explosive is extremely accompanied by danger. Therefore, we developed the electric discharging device made to generate the underwater shock wave. It is easier to carry on the experiment using this device than the experiment of an explosive. We developed a pressure vessel for generating the underwater shock wave in various fields. The developed pressure vessel has been improved by our research group. The pressure vessel made to generate the shock wave is manufactured from a new concept, and the coaxial cable is used for wiring of the device.

Author(s):  
Ken Shimojima ◽  
Yoshikazu Higa ◽  
Osamu Higa ◽  
Ayumi Takemoto ◽  
Shigeru Itoh ◽  
...  

Recently, National Institute of Technology, Okinawa College (ONCT) has been developing a new food processing method using underwater shock wave. The continuous-operation device was manufactured for the production of rice flour, the amount of milling flour per hour and the quality of the rice powder were evaluated. In the case of Yuzu (Citrus junos), an improved fragrance was obtained using this methods compared with other general processing method. The authors have also developed a batch-type crushing device (pressure vessel) for various food processing. However, the mechanism by which is processed using shock waves has not been clarified. Therefore, in this study, the propagation characteristics of a shock wave in the developed pressure vessel were evaluated by numerical simulation. The characteristics of processing is evaluated using shock wave and, the pressure resistance of the vessel was analyzed. In addition, food processing experiments using the developed device were performed. In which, in which “Yuzu” were crushed. Yuzu before-and-after crushing were compared, and the effect of shock wave were clarified.


Author(s):  
Hirofumi Iyama ◽  
Masatoshi Nishi ◽  
Yoshikazu Higa ◽  
Ken Shimojima ◽  
Osamu Higa ◽  
...  

The explosive forming is a characteristic forming method. An underwater shock wave is generated by underwater explosion of the explosive. A metal plate is affected high strain rate by the shock loading and is formed along a metal die. Although this method has the advantage of mirroring the shape of the die, a free forming was used in this paper. An expensive metal die is not necessary for this free forming. It is possible that a metal plate is formed with simple supporting parts. However, the forming shape is depend on the shock pressure distribution act on the metal plate. This pressure distribution is able to change by the shape of explosive, a mass of explosive and a shape of pressure vessel. On the other hand, we need the pressure vessel for food processing by the underwater shock wave. Therefore, we propose making the pressure vessel by the explosive forming. One design suggestion of pressure vessel made of stainless steel was considered. However, we cannot decide suitable conditions, the mass of the explosive and the distance between the explosive and the metal plate to make the pressure vessel. In order to decide these conditions, we have tried the numerical simulation of this explosive forming. The basic simulation method was ALE (Arbitrary Laglangian Eulerian) method. Mie-Grümeisen EOS (equation of state), JWL EOS, Johnson-Cook constitutive equation for a material model were applied in the numerical simulation. In this paper, the underwater pressure contours to clear the propagations of the underwater shock wave, forming processes and deformation velocity of the metal plate is shown and it will be discussed about those results.


Author(s):  
Y. Miyafuji ◽  
K. Shimojima ◽  
S. Tanaka ◽  
K. Naha ◽  
T. Aka ◽  
...  

We have been researching the food processing technology by using the underwater shock wave. The rice-powder used for various foods has been demanded in Japan now. The purpose of this study is designing and development of the pressure vessels for the manufacturing rice-powder device using the underwater shock wave. The pressure vessel was made into the oval shape which focuses the energies generated under the underwater shock wave. The speed and pressure of the shock wave which were generated underwater are confirmed with a high speed camera. The durability and performance of this device is confirmed by manufacturing the rice-powder.


Author(s):  
Masahiko Otsuka ◽  
Toshiaki Watanabe ◽  
Shigeru Itoh

In this study, it has aimed at the design of the pressure vessel where an underwater shock wave is applied to food efficiently. This study aims at the desigh of a pressure vessel in which the underwater shock wave generated by the underwater explosion of detonating fuse was experimentally investigated by the optical observation and the pressure measurement. Therefore the pressure vessel is designed so that suitable pressure may apply on food. This designed vessel is evaluated by the numerical analysis that used LS-DYNA3D. The interaction of the underwater shock wave, the incident wave and the reflected wave are investigated by the numerical analysis. The agreement between the experimental results and the numerical analysis was found to be good.


Author(s):  
Hirofumi Iyama ◽  
Yoshikazu Higa ◽  
Shigeru Itoh

In this study, it has aimed at the design of the pressure vessel for food processing using an underwater shock wave. This study aims at the design of a pressure vessel in which the underwater shock wave generated by the underwater explosion of high explosive was experimentally investigated by the optical observation and the pressure measurement. Therefore the pressure vessel is designed so that suitable pressure may apply on food. This designed vessel is evaluated by the numerical simulation. The interaction of the underwater shock wave, the incident wave and the reflected wave are investigated by the numerical simulation.


2013 ◽  
Vol 767 ◽  
pp. 132-137
Author(s):  
Hirofumi Iyama ◽  
Yoshikazu Higa ◽  
Shigeru Itoh

Explosive forming is one of the unconventional techniques, in which, most commonly, the water is used as the pressure transmission medium. The explosive is set at the top of the pressure vessel filled with water, and is detonated by an electric detonator. The underwater shock wave propagates through the water medium and impinges on the metal plate, which in turn, deforms. There is another pressure pulse acting on the metal plate as the secondary by product of the expansion of the gas generated by detonation of explosive. The secondary pressure pulse duration is longer and the peak pressure is lower than the primary shock pressure. However, the intensity of these pressure pulse is based also on the conditions of a pressure vessel. In order to understand the effects of the configuration of the pressure vessel on the deformation of a metal plate, numerical simulation was performed. This paper reports those results.


2010 ◽  
Vol 4 (2) ◽  
pp. 113-124 ◽  
Author(s):  
Hideki Hamashima ◽  
Manabu Shibuta ◽  
Yosuke Nishimura ◽  
Shigeru Itoh

Author(s):  
Hirofumi Iyama ◽  
Masatoshi Nishi ◽  
Yoshikazu Higa

The explosive forming is a characteristic forming method. This technique is a metal forming using an underwater shock wave. The underwater shock wave is generated by underwater explosion of the explosive. The metal plate is formed with involving the high strain rate on this technique. In generally, the pressure vessel is used in this method due to the effective utilization of the explosion energy. The underwater shock wave is propagated in water and reflected on inside wall of the pressure vessel. This reflected shock wave is affected on the deformation shape of a metal plate. Therefore, the inside shape of pressure vessel is often changed. In other words, the shape of pressure vessel is changed, the shock pressure distribution on the metal plate and it is possible that final deformation shape of the metal plate is changed. Some numerical simulations and experiments have been carried out to clear the influence of the inside shape of pressure vessel in the explosive forming. This paper is included the results and discussions on the numerical simulation and experiment used those conditions.


2013 ◽  
Vol 767 ◽  
pp. 265-268
Author(s):  
Hironori Maehara ◽  
Seisaku Iwasa ◽  
Toshiaki Watanabe ◽  
Kazuyuki Hokamoto ◽  
Shigeru Itoh

In recent years, a method of food processing using underwater shock wave has been investigated. The underwater shock wave is generated by high voltage and large current gap discharge in water, and it is used for food processing in the present investigation. When the underwater shock wave is loaded on the food, the food cells are momentarily broken. Therefore, the food becomes soft, and possible to squeeze water easily. Also, seasonings can be penetrated inside of the food. The improvement of absorbing seasonings for the shock processed foods mainly on Japanese radish is reported in this paper.


Sign in / Sign up

Export Citation Format

Share Document