Yoshitaka Miyafuji

National Institute of Technology, Gifu College

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Izuru Senaha

University of the Ryukyus

Shigeru Itoh

Nagoya University

K. Naha

National Institute of Technology Okinawa College

Minoru Yaga

University of the Ryukyus

Sumio Kato

Akita University

Shigeru Tanaka

Kumamoto University

Kenyu Oyakawa

University of the Ryukyus

K. Shimojima

National Institute of Technology Okinawa College

Munehiko Hiwada

Gifu University

Shôichi Matsuda

National Institute for Materials Science

Cooperative Institutions

National Institute of Technology Okinawa College

University of the Ryukyus University Hospital

Kumamoto University

National Institute of Technology

University of the Ryukyus

The University of Tokyo

Kyushu University

National Institute of Technology, Yonago College

Gifu University

Kyoto University

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Study of the Suitable Pressure Vessel for the Rice-Powder Manufacturing Using the Underwater Shock Wave

K. Shimojima Yoshitaka Miyafuji Shigeru Tanaka K. Naha T. Aka

Self-sufficiency in food is very low (about 40%) in Japan. Therefore, the rice powder is paid to attention, because it can be processed to the udon (noodle) and bread etc. We have already developed the rice-powder disintegrator using the underwater shock wave by the electrode. But it has not been cleared what is the most suitable pressure vessel. The purpose of this study is to investigate the most suitable configuration of the pressure vessels for manufacturing the rice-powder using the underwater shock wave.Experimental conditions to manufacture the rice-powder (particle size is 100μm) is clarified using this device.Moreover, the manufacturing efficiency of the rice-powder, the relation between the number of the shock wave generation and the grain degree of rice-powder is clarified.

Clearance

10.1115/pvp2011-58032

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Citations (5)

507 The numerical analysis of Thermal and Fluid flow for solidification process of the casting

Keisan Rikigaku Koenkai koen ronbunshu/Keisan Rikigaku Kouenkai kouen rombunshuu (2008)

Yoshitaka Miyafuji Osamu Makishi Hidemi Shirakawa

This paper shows that numerical analysis for thermal and fluid flow with phase change in casting, and the two-dimensional temperature distribution analysis by the infrared camera. Navier-Stokes and energy equation are solved simultaneously both for liquid and solid phase. The volume of fluid method is introduced into this numerical analysis. This method is performing interface movement using the rate of volume of the liquid which exists in inspection volume. Therefore, it is known that this method has the sufficient preservability of volume. In this study, the volume of fluid method is applied to the numerical analysis of the solidification process in the aluminum casting. As a result of performing numerical analysis, the temperature distribution and the solidification distribution are shown in this paper. Furthermore, thermal and fluid flow for solidification of the aluminum casting are visualized by using an infrared camera and a video camera.

10.1299/jsmecmd.2008.21.217

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Industry-academia Collaboration by Engineering Experiment

Journal of JSEE (2011)

Kiyotaka MASAKI Yoshitaka Miyafuji

Engineering experiment is one of the most important components in the mechanical engineering education because it is possible to make students acquire the basis of engineering, the use of devices and the writing skill of reports. Engineering experiment also has an advantage that many experimental data can be obtained during the school hours. This report introduces a trial of the industry-academia collaboration using the advantages of the engineering experiment in Mechanical System Engineering of the Okinawa National College of Technology. As a result of the trial, it is cleared that the useful data comparable to those in graduation research are obtained thorough engineering experiment. In addition, this trial has a highly educative effect improving the motivation and the concentration of students on the experiment by explaining the purpose of the experiment.

10.4307/jsee.59.2_22

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Visualization of Flow inside a Redox Flow Battery Using a Thermography

The Proceedings of Mechanical Engineering Congress Japan (2020)

Yasuo Kasuga Yoshitaka Miyafuji Hiroshi Tanaka

Thermography

Flow battery

10.1299/jsmemecj.2020.s05419

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Heat transfer enhancement in duct with blunt body inserted close to its wall

Proceedings of thermal engineering conference (2002)

Yasuaki Kourogi Minoru Yaga Yoshitaka Miyafuji Kenyu Oyakawa

In present paper, we investigated the effects of clearance length between a body and a duct wall, and duct height on the heat transfer characteristics and flow behavior at downstream region of body when the blunt body was set in parallel plate duct with some distance separating it from the duct wall as a turbulence promoter. At the ratio of clearance to body height, C/D=0.05∿0.1,the heat transfer was characterized by the reattachment of shear flow separated from the body. Furthermore, the heat transfer depended on both effects of the reattachment flow and the separation vortex at C/D=0.15,and effect of the separation vortex generated by separating flow through the clearance or the side vortex induced by Karman vortex at C/D=0.2 and 0.25.

Tip clearance

Heat transfer enhancement

10.1299/jsmeptec.2002.0_39

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Heat transfer enhancement in duct with blunt body inserted close to its wall

Heat Transfer-Asian Research (2005)

Kenyu Oyakawa Yasuaki Kourogi Minoru Yaga Yoshitaka Miyafuji

Heat transfer enhancement

10.1002/htj.20067

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Improvement of Extracted Volume of Sugarcane Using Underwater Shock Wave

K. Shimojima K. Naha Yoshitaka Miyafuji Eisuke Kuraya Kenta Watanabe

The productivity improvement of food is necessary because the rate of food self-sufficiency of Japan is low. And then, the high efficient food processing is developed in Japan. On the other hand, the ratio of the production of sugarcane is high in the primary industry in Okinawa Prefecture. The rate of profit in the sugar manufacturing by sugarcane is lower than other primary industry goods, because the production cost is high. In this research, the sugar manufacturing method by sugarcane in high efficiency was developed using underwater shockwave. In this paper, to crush hard food like sugarcane, the pressure vessels of three dimensional oval structure is proposed. It is clear that the effect of the improvement of the juice extraction rate using the pressure vessel.

Sugar industry

Production rate

10.1115/pvp2012-78417

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D224 The heat transfer enhancement mechanism on the forced convection by spraying a slight quantity of mist

The Proceedings of the Thermal Engineering Conference (2012)

Izuru Senaha Masaki HIGA Yoshitaka Miyafuji Sumio Kato Shôichi Matsuda

This paper describes the heat transfer enhancement mechanism on the forced convection by spraying a slight quantity of mist in a channel of a backward-facing step flow. The mist reduces temperature of a main flow by displacement of the latent heat accompanying evaporation. In this research, about the above-mentioned phenomenon was done by both of the experiment and the computer simulation. And, we compared those results and considered that about the relation of the behavior and evaporation process of the mist. Finally, about the mechanism of the heat transfer enhancement by spraying a slight quantity of mist in a recirculation region was discussed.

Mist

Forced convection

Heat transfer enhancement

10.1299/jsmeted.2012.391

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Basic Study on Heat Transfer of Intermittent Impingement Jet for Electronic Equipment Cooling

The Proceedings of the Thermal Engineering Conference (2019)

Yoshitaka Miyafuji Takashi Fukue Hidemi Shirakawa Wakana Hiratsuka Shintaro Hayakawa

10.1299/jsmeted.2019.0127

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S053072 Measurement of Time and Spatial Characteristics of Heat Transfer and Fluid Flow with Mist in the Region behind the Backward-Facing Step

The Proceedings of Mechanical Engineering Congress Japan (2012)

Masaki HIGA Yoshitaka Miyafuji Izuru Senaha Sumio Kato Takune KAWAHIRA

This study is about the heat transfer enhancement in a backward-facing step flow with a little amount of mist.In the forced convection place which used the air flow, a little amount of mist is made to mix to the separated-shear-layer and the spatial temperature in the channel is decreased by using the evaporation latent heat of the mist. Therefore, a thermal boundary layer can be changed without changing a velocity profile and it does not cause pressure loss. The experiments were conducted to examine the effects of thermal and flow field in the channel by changing amount of mist using Infrared Camera and High-speed camera. It is concluded that changing amount of mist supply is effective to enhance the heat transfer.

Mist

10.1299/jsmemecj.2012._s053072-1

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