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Aoki, Takayuki*; Hasegawa, Yuta
Jidosha Gijutsu, 74(4), p.18 - 23, 2020/04
Aerodynamics studies for bicycle racings have been carried out by using a CFD simulation based on LES model. For running of alone cyclist and 2-4 cyclists groups, the computational drags are in good agreement with the wind-tunnel experiments. Different shapes of group running and competing two teams are studied. A large-scale computation for a group of 72 cyclists has been performed by using 2.23 billion meshes on a GPU supercomputer.
Sugiyama, Hitoshi*; Takahashi, Keita*; Kato, Naoto*; Terada, Atsuhiko; Kamiji, Yu; Hino, Ryutaro
Jidosha Gijutsukai Gakujutsu Koenkai Zensatsushu, (109-14), p.5 - 10, 2014/10
Numerical analysis has been performed for vertical buoyant flow of air-hydrogen mixture in rectangular indoor space with ventilators. The unsteady and laminar flow has been calculated by using the coupled conservation equations of hydrogen and momentum. Calculated results are compared with the experiment data of hydrogen concentration and velocity profile in order to confirm the validity of the presented numerical method and clarify the mechanism of hydrogen dispersion. Although agreement is certainly not perfect in all detail, the main features are reasonably reproduced. Adding to this, calculated results suggest that hydrogen concentration depends on Froude number.
Sugiyama, Hitoshi*; Otemori, Toshiki*; Kato, Naoto*; Terada, Atsuhiko; Kamiji, Yu; Hino, Ryutaro
Jidosha Gijutsukai Gakujutsu Koenkai Zensatsushu, (147-14), p.25 - 30, 2014/10
Numerical analysis has been performed for three-dimensional developing turbulent flow in a rectangular duct containing straight cylinder placed near a bottom wall. In this kind of turbulent flow, it has been pointed out as a characteristic features that anisotropic turbulence generates the secondary flow of the second kind and pulsation flow is measured in narrow gap region located between cylinder and bottom wall. Comparisons with the experimental results suggest that the present method is able to predict velocity profiles correctly and reproduce both the secondary flow of the second kind and the generation of pulsation flow near the narrow region between cylinder and bottom wall.
Okagaki, Yuria*; Sugiyama, Hitoshi*; Kato, Naoto*; Hino, Ryutaro
Jidosha Gijutsukai Rombunshu, 43(4), p.949 - 955, 2012/07
Turbulent heat transfer enhancement using periodically arranged ribs processed on the graphite sleeve of a fuel rod aims to increase heat generation density of the fuel rod, which can potentially improve the economics of a block type high-temperature gas-cooled reactor. Rectangular cross section of rib is selected because of easy processing. Furthermore, it is important to find optimum rib topology such as pitch and height to maximize turbulent heat transfer performance. In order to develop a turbulent model as a design tool for rib-roughened fuel rod, numerical analysis has been conducted to verify applicability of an algebraic Reynolds stress model, which is computationally efficient, to non-isotropic turbulent flow in rib roughened channels. The results of the analysis on a square duct with periodically arranged ribs on the bottom wall are shown to reproduce very well the flow characteristics such as flow separation and reattachment behind the ribs. The model is therefore expected to be applicable to rib-enhanced fuel rod design.
Kureta, Masatoshi; Segawa, Mariko
Jidosha Gijutsukai Shimpojiumu Tekisuto, No.9-11, p.24 - 29, 2012/01
The neutron imaging technique is a one of the unique and advanced non-destructive visualization and measurement techniques. In this symposium, the principle, its application and hot information about the puled neutron imaging by using J-PARC are presented. Its applications to a car engine and a differential are introduced. High-frame-rate imaging, 3D and 4D CT imaging, velocimetry by the PTV method and advanced pulsed neutron imaging are shown as the technology catalog.
Seko, Noriaki
Jidosha Gijutsu, 63(11), p.102 - 105, 2009/11
Our objective focuses on the development of fibrous adsorbent for rare metals such as scandium and vanadium by means of radiation-induced graft polymerization and their adoption to recovery from hot spring water in Kusatsu-spa.
Egusa, Shigenori
Jidosha Gijutsu, 50(6), p.69 - 70, 1996/00
no abstracts in English
Jidosha Gijutsu, 42(11), p.1386 - 1387, 1988/11
no abstracts in English
