Basic Study on the Crushing of Frozen Soil by Shock Loading

2007 ◽  
Author(s):  
Toshiaki Watanabe ◽  
Hironori Maehara ◽  
Masahiko Otsuka ◽  
Shigeru Itoh
Keyword(s):  
Shock Wave ◽  
High Speed ◽  
Shock Loading ◽  
Underwater Explosion ◽  
Frozen Soil ◽  
High Speed Camera ◽  
Underwater Shock Wave ◽  
Basic Study ◽  
Underwater Shock ◽  
A New Technique

The aim of study is to confirm a new technique that can crush the frozen soil and/or ice block using underwater shock wave generated by the underwater explosion of explosive. This technique can lead to the earlier sowing, which can have the larger harvest because the duration of sunshine increases. Especially, in Hokkaido prefecture, Japan, if the sowing is carried out in April, we can expect to have 150% of harvest in the ordinary season. This technique is effective against the cold regions. For example, Korea, China, Mongolia, Russia, Norway, and Sweden, etc. At first, we carried out experiments usung a detonating fuse and ice block. The process of ice breaking was observed by means of a high-speed camera. In order to check about that influence we tried to give an actual frozen soil a shock wave.

Basic Study for Crushing of Frozen Soil by Underwater Shock Wave

2003 ◽  
Author(s):  
Toshiaki Watanabe ◽  
Shigeru Itoh ◽  
Toru Hamada ◽  
Osamu Kiyama ◽  
Yutaka Kuroyama ◽  
...  
Keyword(s):  
Shock Wave ◽  
High Speed ◽  
Underwater Explosion ◽  
Frozen Soil ◽  
Cold Region ◽  
Underwater Shock Wave ◽  
Basic Study ◽  
Sunshine Hours ◽  
Underwater Shock ◽  
A New Technique

The final aim of study is confirm a new technique that can crush frozen soil and/or ice on the farm by underwater shock wave generated underwater explosion of explosive. In the cold region, for example, North Japan, Russia, Norway, and Sweden, etc., this technique can makes carry out early sowing and having large harvest. Especially, in Hokkaido prefecture Japan, if sowing is carried out in April, we may be expected to have a 150% of harvest of ordinary season due to the total of the sunshine hours. At first, we carried out experiments, which use detonating cord and ice block for the case of shock wave that collides aslant to ice. We obtained result that strength of the ice strongly depends on existence of bubble in the ice. So, we carried out experiments, which use explosive and ice block for the case of shock wave that collides verticality to ice. And, as the first step of pressure measurement, we experimented using the plate device that can detect shock wave. The process of breaking of ice was observed by using of the high-speed camera.

Promotion of Thawing Frozen Soil by Shock Wave Loading

2013 ◽  
Vol 767 ◽  
pp. 205-210
Author(s):  
Toshiaki Watanabe ◽  
Hideki Hamashima ◽  
Hironori Maehara ◽  
Kazuyuki Hokamoto ◽  
Shigeru Itoh
Keyword(s):  
Shock Wave ◽  
Shock Loading ◽  
Underwater Explosion ◽  
Water Layer ◽  
Frozen Soil ◽  
Shock Wave Loading ◽  
Wave Loading ◽  
Underwater Shock Wave ◽  
Underwater Shock ◽  
A New Technique

The aim of study is to confirm a new technique that can crush the frozen soil and/or ice block using underwater shock wave generated by the underwater explosion of explosive. This technique can lead to the earlier sowing, which can have the larger harvest because the duration of sunshine increases. Especially, in Hokkaido prefecture, Japan, if the sowing is carried out in April, we can expect to have 150% of harvest in the ordinary season. This technique is effective against the cold regions, for example, Russia, Norway, and Sweden, etc. In order to check about that influence we tried to give an actual frozen soil a shock wave. We could get a result that existence of water layer serves an important role in promotion of thawing by the shock loading to the frozen soil. That role was confirmed from the result of numerical simulation.

Basic Study for Crushing of Ice by Underwater Shock Wave

2007 ◽  
Vol 566 ◽  
pp. 243-248 ◽  
Author(s):  
Toshiaki Watanabe ◽  
Hironori Maehara ◽  
Shigeru Itoh
Keyword(s):  
Shock Wave ◽  
High Speed ◽  
Underwater Explosion ◽  
Snow Melting ◽  
Underwater Shock Wave ◽  
Basic Study ◽  
Underwater Shock ◽  
A New Technique ◽  
Quantity Of Heat ◽  
On Farm

The aim of this study is to confirm a new technique that can crush ice by underwater shock wave generated by underwater explosion of explosive. Damage caused by ice occurs in the cold regions at different circumstances. For example, the problems such as accretion of ice on the drainage of snow melting system, on the ship and on farm lands. The solution for such problems is to use a method of heating. As the necessary quantity of heat is enormous and the problem of global warming exists, the dynamic way of solving is desirable. At first, we carried out experiments using detonating cord and ice block. The process of propagation of shock wave in ice was observed by using the high-speed camera.

Exfoliation of Marine Organisms Technology by Using Underwater Shock Wave

2005 ◽  
Author(s):  
Toshiaki Watanabe ◽  
Hirofumi Iyama ◽  
Ayumi Takemoto ◽  
Shigeru Itoh
Keyword(s):  
Shock Wave ◽  
High Speed ◽  
Marine Organisms ◽  
High Speed Camera ◽  
Sluice Gate ◽  
Underwater Shock Wave ◽  
Manual Operation ◽  
Fluid Resistance ◽  
Personnel Expenses ◽  
Underwater Shock

Adhesion problem of marine organisms often becomes a problem, in the case of ship, marine floating construction and sluice gate of power plant. These make fluid resistance of a hull increase, cause a buoyancy fall, or cause reducing coolant etc. Although these are chiefly removed by manual operation now, immense expense and immense labors, such as personnel expenses and time and effort, are needed. We tried application of an underwater shock wave, in order to solve these problems. Interference of a shock wave and the mechanism of marine organisms exfoliation were explored using the explosive and PMMA plate, which imitated a marine organisms adhesion. The process of exfoliation of organisms from PMMA plate was observed by using of the high-speed camera.

Deformation Mechanism of Metal Plate on Explosive Forming

2005 ◽  
Author(s):  
Hirofumi Iyama ◽  
Takeshi Hinata ◽  
Shigeru Itoh
Keyword(s):  
Numerical Simulation ◽  
Shock Wave ◽  
High Speed ◽  
Underwater Explosion ◽  
Metal Plate ◽  
Sufficient Accuracy ◽  
Underwater Shock Wave ◽  
Underwater Shock ◽  
Explosive Forming ◽  
Forming Methods

The explosive forming is one of the forming methods of a metal plate performed since the 1950s. This method is different from usual static press forming. The metal plate is accelerated by underwater shock wave, which is generated by underwater explosion of an explosive. In order to deform a metal plate in predetermined form with sufficient accuracy using this forming method, it is important to grasp the mechanism. At first, it is necessary to grasp that an underwater shock wave spreads and it collides with the metal plate. And it is also necessary to show clearly what deformation of the metal plate with high-speed. Then, we investigated about the mechanism in the numerical simulation. In this research, LS-DYNA, which is the software for shock analysis was used. Moreover, the experiment was also conducted in order to confirm whether this numerical simulation is exact.

Destruction of Concrete Block Using Underwater Shock Wave Generated by Electric Discharge

2006 ◽  
Author(s):  
Masahiko Otsuka ◽  
Shigeru Itoh
Keyword(s):  
Shock Wave ◽  
Electric Discharge ◽  
High Voltage ◽  
High Speed ◽  
Concrete Block ◽  
Metal Wire ◽  
High Speed Camera ◽  
Underwater Shock Wave ◽  
Underwater Shock ◽  
Made In

In this study, the destruction of concrete block using underwater shock wave generated by electric discharge was studied. Initially, the shock wave generated by electric discharge was investigated by optical observation using a high-speed camera and pressure measurement. A comparison of the underwater shock wave generated from the electrode with and without connecting a metal wire was made. A metal wire was connected to an electrode and a high voltage impulsive current was passed through it to generate the underwater shock wave. A hole was made in the concrete block, filled with water and an electrode was inserted into the hole, which acts as a pressure vessel. The electric current was passed through this electrode to generate underwater shock wave for the destruction of concrete block.

Numerical Simulation for Development of Pressure Vessel for Food Processing by Shock Loading

2006 ◽  
Author(s):  
Masahiko Otsuka ◽  
Toshiaki Watanabe ◽  
Shigeru Itoh
Keyword(s):  
Numerical Simulation ◽  
Shock Wave ◽  
Numerical Analysis ◽  
Pressure Vessel ◽  
Food Processing ◽  
Shock Loading ◽  
Underwater Explosion ◽  
Underwater Shock Wave ◽  
Reflected Wave ◽  
Underwater Shock

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.

Behavior of Bubble in Small Water Tank Used for Food Processing Using Underwater Shock Wave

2011 ◽  
Vol 673 ◽  
pp. 225-230 ◽  
Author(s):  
Hideki Hamashima ◽  
Manabu Shibuta ◽  
Shigeru Itoh
Keyword(s):  
Numerical Simulation ◽  
Shock Wave ◽  
Food Processing ◽  
High Speed ◽  
Underwater Explosion ◽  
Video Camera ◽  
Experimental Result ◽  
Water Tank ◽  
Underwater Shock Wave ◽  
Small Water

The food processing technology using a shock wave can prevent deterioration of the food by heat because it can process food in a short time. Generally, since the shock wave used for food processing is generated by underwater explosion, the load of a shock wave to the food becomes very complicated. Therefore, in order to process safely, it is important to clarify the behaviors of the shock wave and the bubble pulse generated by underwater explosion. In this research, in order to investigate the behavior of the shock wave in the water tank used for food processing, the optical observation experiment and the numerical simulation were performed. In the experiment, the shock wave generated by underwater explosion was observed with the high-speed video camera. The numerical simulation about the behavior of bubble pulse was performed using analysis software LS-DYNA. Comparing and examining were performed about the experimental result and the numerical simulation result. The result of the numerical simulation about the behavior of the shock wave generated by underwater explosion and the shock wave generated by the bubble pulse and the bubble pulse was well in agreement with the experimental result.

On Crushing of Frozen Soil by Underwater Shock Wave

2002 ◽  
Author(s):  
Toshiaki Watanabe ◽  
Shigeru Itoh ◽  
Toru Hamada ◽  
Yutaka Kuroyama ◽  
Akira Nakachi
Keyword(s):  
Shock Wave ◽  
Frozen Soil ◽  
Underwater Shock Wave ◽  
Underwater Shock

A Study of Developing Composite Material of Penetrated Diamond Particles Into Metal Plate

2009 ◽  
Author(s):  
Keijiro Nishi ◽  
Shigeru Tanaka ◽  
Shigeru Itoh
Keyword(s):  
Thermal Conductivity ◽  
Shock Wave ◽  
Composite Material ◽  
High Speed ◽  
High Hardness ◽  
Optical Microscope ◽  
Metal Plate ◽  
Underwater Shock Wave ◽  
Diamond Particles ◽  
Underwater Shock

An explosive welding technique which uses underwater shock wave to weld thin aluminum plate has been studied and the technical advantages were reported. In this research, we propose a method to produce a composite material using an underwater shock wave generated by detonation of explosive. In the production process, a metal plate (flyer plate) accelerates to a high speed by the underwater shock wave, and collided with diamond particles and penetrated the metal plate. Diamonds were used as the particles and aluminum plates (A1050) as the flyer plates. Diamond has high hardness and excellent thermal conductivity, therefore diamond should provide improvement in the thermal conductivity of the composite material. From recovered sample, the multilayer joined surface including diamond particles was observed using an optical microscope. The production of the pipe of composite materials was attempted using this technique as the application. Details of the experimental methods and results are reported in this paper.

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