Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Maeyama, Shinya*; Watanabe, Tomohiko*; Idomura, Yasuhiro; Nakata, Motoki*; Nunami, Masanori*
Computer Physics Communications, 235, p.9 - 15, 2019/02
Times Cited Count：5 Percentile：45.72(Computer Science, Interdisciplinary Applications)We have implemented the Sugama collision operator in the gyrokinetic Vlasov simulation code, GKV, with an implicit time-integration scheme. The new method is versatile and independent of the details of the linearized collision operator, by means of an operator splitting, an implicit time integrator, and an iterative Krylov subspace solver. Numerical tests demonstrate stable computation over the time step size restricted by the collision term. An efficient implementation for parallel computation on distributed memory systems is realized by using the data transpose communication, which makes the iterative solver free from inter-node communications during iteration. Consequently, the present approach achieves enhancement of computational efficiency and reduction of computational time to solution simultaneously, and significantly accelerates the total performance of the application.
Takata, Takashi; Yamaguchi, Akira
JNC TN9400 2000-065, 152 Pages, 2000/06
JNC-TN9400-2000-065.pdf:6.26MBJNC-TN9400-2000-065(errata).pdf:0.12MB
ln the liquid metal fast reactor (LMFR) using liquid sodium as a coolant, it is important to evaluate the effect of the sodium combustion on the structure, etc. Most of the previous analytical works are based on a zone model, in which the principal variables are treated as volume-average quantities. Therefore spatial distribution of gas and structure temperatures, chemical species concentration are neglected. Therefore, a multi-dimensional sodium combustion analysis code AQUA-SF (Advanced simulation using Quadratic Upstream differencing Algorithm - Sodium Fire version) has been developed for the purpose of analyzing the sodium combustion phenomenon considering the multi-dimensional effect. This code is based on a multi-dimensional thermal hydraulics code AQUA that employs SIMPLEST-ANL method. Sodium combustion models are coupled with AQUA; one is a liquid droplet model for spray combustion, and the other is a flame sheet model for pool combustion. A gas radiation model is added for radiation heat transfer. Some other models necessary for the sodium combustion analysis, such as a chemical species transfer, a compressibility, are also added. ln AQUA-SF code, bounded QUICK method in space scheme and bounded three-point implicit method in time scheme are implemented. Verification analyses of sodium combustion tests shown in the following have been carried out. (1)pool combustion test (RUN-D1) (2)spray combustion test (RUN-E1) (3)sodium leakage combustion test (Sodium Fire Test-II) (4)smaII-scale leakage combustion test (RUN,F7-1) ln each verification analysis, good agreements are obtained and the validity of AQUA-SF code is confirmed.
; Azumi, Masafumi; Takeda, Tatsuoki
JAERI-M 93-004, 50 Pages, 1993/02
no abstracts in English
Watanabe, Tadashi; Kukita, Yutaka
Numerical Modelling of Basic Heat Transfer Phenomena in Nuclear Systems, p.25 - 30, 1991/00
no abstracts in English
Hirano, Masashi
Nisoryu Suchi Kaisekiho No Kiso To Oyo, p.202 - 218, 1989/00
no abstracts in English
Asahi, Yoshiro; Hirano, Masashi;
JAERI 1300, 172 Pages, 1986/12
no abstracts in English
Asahi, Yoshiro; *
Journal of Nuclear Science and Technology, 21(9), p.657 - 670, 1984/00
Times Cited Count：4 Percentile：45.49(Nuclear Science & Technology)no abstracts in English
