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Hidetoshi Hashizume Graduate School of Engineering
Nano-Materials and Processing |
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| Development of remountable HTc superconducting magnet Since operating temperature of HTc superconducting tape is relatively high, the specific heat of the material becomes large enough to stand for heat generation around the jointing. The optimized mechanical jointing method is being developed to reduce the electric resistance and it is expected that nano technology can improve the contact resistance. By developing the remountable magnets, we can expect not only easy fabrication process of relatively complicated magnet system as is needed in helical reactor but also easy replacement of damaged magnet. Development of high heat removal technology Recently, effective heat removal system is needed because of high performance of computer, compactness of several engineering component and so on. Especially, a first wall, a divertor and a limiter (i.e. plasma facing component) in fusion reactor, which is expected as a new energy source in future, is required to underbear severe circumstances with the extremely high heat flux and high particle loads. To achieve the high heat removal technology over 100MW/m2, experimental and numerical study on porous media is mainly performed and evaluated. Research on heat-transfer enhancement for high Pr-number fluid Although high Pr-number fluid generally indicates the low heat-transfer performance because of its low heat conductivity and high viscosity, molten salt Flibe, which is high Pr-number fluid, has been recommended as an alternative candidate material for liquid blanket of fusion reactor from the viewpoint of avoiding MHD effects. Consequently, heat transfer enhancement for high Pr-number fluid must be achieved. In order to clarify the heat-transfer characteristics and to establish its handling and enhancing techniques, numerical and experimental research has been implemented by using high temperature molten salt HTS that is simulant for Flibe. Evaluation of thermofluid mixing characteristics for two fluids with different temperatures In a region where two fluids with different temperatures are mixed together, unsteady temperature fluctuation occurs in going through the mixing process of the fluids, and structural materials in the surrounding area are damaged by high-cycle thermal fatigue. This phenomenon is called thermal striping and often becomes an important technical issue in nuclear power plants. In order to elucidate the relationship between the fluid mixing and the wall-temperature fluctuation, the fluid mixing characteristics in the T-junction area have been evaluated by visualization experiment using a PIV (Particle Image Velocimetry) system, i.e. a non-contact measuring technique using a laser sheet. Development of non-destructive testing for crack detection with microwave To use fission reactors for a long term, which contributes to reducing both electric cost and carbon dioxide emission, it is necessary to develop the non-destructive testing (NDT) method for crack detection with high speed and high accuracy to guarantee the safety of the plants. The new NDT method using microwave propagation has been developed to detect the crack location inside the pipings.
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