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Yamada, Tomonori
Nihon Kikai Gakkai Dai-21-Kai Keisan Rikigaku Koenkai Rombunshu (CD-ROM), p.894 - 895, 2008/11
Convergence performance of coarse grid correction approach in structured coarse grid correction and balancing domain decomposition is investigated in this paper. In the extra large scale finite element analysis with more than a billion degrees of freedom, it is difficult to solve large scale coarse gridproblem with direct solution approach. Hence, the number of degrees of freedom in coarse grid is restricted in terms of computation resources. In this paper, the convergence performance of coarse grid correction with coarser coarse grid is studied through some numerical examples.
Yamaguchi, Masatake; Ebihara, Kenichi; Suzudo, Tomoaki; Itakura, Mitsuhiro; Kaburaki, Hideo
Nihon Kikai Gakkai Dai-21-Kai Keisan Rikigaku Koenkai Rombunshu (CD-ROM), p.35 - 36, 2008/11
no abstracts in English
Ida, Masato; Naoe, Takashi; Futakawa, Masatoshi
Nihon Kikai Gakkai Dai-21-Kai Keisan Rikigaku Koenkai Rombunshu (CD-ROM), p.572 - 573, 2008/11
Cavitation in liquid mercury and resulting damage of mercury vessels are significant problems in the development of spallation neutron sources. In the present paper we study numerically the effect of "bubble injection" that we are now attempting to suppress cavitation damage. By numerical analysis that takes bubble-bubble interaction into account, we have found that (1) the injected bubbles decreases the magnitude of the negative pressure generated in mercury, (2) thereby the inception of cavitation is suppressed, and (3) the injected bubbles hardly cause damage because their expansion ratio and collapse velocity are small.