Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Ishizawa, Akihiro*; Idomura, Yasuhiro; Imadera, Kenji*; Kasuya, Naohiro*; Kanno, Ryutaro*; Satake, Shinsuke*; Tatsuno, Tomoya*; Nakata, Motoki*; Nunami, Masanori*; Maeyama, Shinya*; et al.
Purazuma, Kaku Yugo Gakkai-Shi, 92(3), p.157 - 210, 2016/03
The high-performance computer system Helios which is located at The Computational Simulation Centre (CSC) in The International Fusion Energy Research Centre (IFERC) started its operation in January 2012 under the Broader Approach (BA) agreement between Japan and the EU. The Helios system has been used for magnetised fusion related simulation studies in the EU and Japan and has kept high average usage rate. As a result, the Helios system has contributed to many research products in a wide range of research areas from core plasma physics to reactor material and reactor engineering. This project review gives a short catalogue of domestic simulation research projects. First, we outline the IFERC-CSC project. After that, shown are objectives of the research projects, numerical schemes used in simulation codes, obtained results and necessary computations in future.
Hirota, Makoto; Yoshida, Zensho*
Journal of Math-for-Industry (Internet), 1, p.123 - 130, 2009/10
Perturbations in a shear flow exhibit rather complex behavior - waves may grow algebraically even when the spectrum of disturbances is entirely neutral (no exponential instability). A shear flow brings about non-selfadjoint property, invalidating the standard notion of dispersion relations, and it also produces a continuous spectrum that is a characteristic entity in an infinite-dimension phase space. This paper solves an initial value problem using the Laplace transform and presents a new-type of algebraic instability that is caused by resonant interaction between acoustic modes (point spectrum) and vortical continuum mode (continuous spectrum). Such a resonance is possible when variation of velocity shear is comparable to sound speed.
Shiraishi, Junya; Yoshida, Zensho*; Furukawa, Masaru*
Astrophysical Journal, 697(1), p.100 - 105, 2009/03
Times Cited Count：5 Percentile：17.83(Astronomy & Astrophysics)A thin disk accompanied by spindle-like jet, created commonly near massive central objects, exhibits a topologically singular aspect when viewed from an ideal macroscopic theory. The accreting inflow and jet's outflow are "singular perturbation" on the ambient Keplerian rotation, which are generated by some non-ideal higher-order (in the order of derivatives) effect. The Hall effect can generate such a structure in a weakly ionized plasma of a protostellar disk. Numerical estimate of the characteristic length scale defined by the singular perturbation justifies the precedence of the Hall effect.
