http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Finite element analysis of 2D turbulent flows using the logarithmic form of the κ-ε model
Hasebe, Hiroshi,Nomura, Takashi Techno-Press 2009 Wind and Structures, An International Journal (WAS Vol.12 No.1
The logarithmic form for turbulent flow analysis guarantees the positivity of the turbulence variables as ${\kappa}$ and ${\varepsilon}$ of the ${\kappa}-{\varepsilon}$ model by using the natural logarithm of these variables. In the present study, the logarithmic form is incorporated into the finite element solution procedure for the unsteady turbulent flow analysis. A backward facing step flow using the standard ${\kappa}-{\varepsilon}$ model and a flow around a 2D square cylinder using the modified ${\kappa}-{\varepsilon}$ model (the Kato-Launder model) are simulated. These results show that the logarithmic form effectively keeps adequate balance of turbulence variables and makes the analysis stable during transient or unsteady processes.
( Hasebe Tsuyoshi ) 한국한문학회 2014 韓國漢文學硏究 Vol.0 No.56
This paper suggests possibility of Dufu(杜甫)``s collection including Munwonyeonghwa(_文苑英華_) which was published in the Northern Song(北宋) dynasty and introduces circumstances of Dufu(杜甫)``s collection flowed to Japan. Dufu(杜甫)``s collection including Munwonyeonghwa(_文苑英華_) belongs to divergent lineage compared to Songbondugongbujip(_宋本杜工部集_). Also Dufu(杜甫)``s collection including Munwonyeonghwa(_文苑英華_) is related to Dufu``s collection of poems compared to Dugongbujipsojip(_杜工部 集小集_) and Dangsiryuseon(_唐詩類選_), because these books contained Dufu``s collection. Meanwhile, there were lots of editions in the Tang(唐) dynasty according to original scripts Dugongbujipsojip(_杜工部集小集_), Dangsiryuseon(_唐詩 類選_) and Munwonyeonghwa(_文苑英華_). When Wonin(圓仁, 794-864) who entered Tang as a foreign student brought two books of Duwonoejip(_杜員外集_) from Tang. As they were not complete Dufu(杜甫)``s collection but collectanea, we can infer that varieties of Dufu``s collection would catch on. Cheonjaegagu(_千載佳句_) included the poem of Dufu in the Heian period(平安時代). Accordingly, these poems showed the same tendency, and reflected trait of Dufu``s collection. In conclusion, varieties of Dufu``s collection independently may distribute and they were not likely to spread extensively in the Tang dynasty. Thus, the Dufu``s collection flowed to Japan and likely to beaccepted them in the Heian period.
Hasebe, T.,Nagashima, S.,Kamijo, A.,Moon, M.W.,Kashiwagi, Y.,Hotta, A.,Lee, K.R.,Takahashi, K.,Yamagami, T.,Suzuki, T. Elsevier 2013 Diamond and related materials Vol.38 No.-
We investigated the hydrophobicity and non-thrombogenicity of a nanoscale dual rough surface coated with hydrophobic and non-thrombogenic fluorine-incorporated diamond-like carbon (F-DLC) films. We prepared Si (1 0 0) and a dual rough surface composed of coarse posts and nano-sized fine posts as substrates. DLC film was deposited on the Si substrate, and F-DLC film was deposited on Si or the dual rough surface using radio frequency plasma enhanced chemical vapor deposition method. The surface hydrophobicity of each sample was examined with water contact angle measurements and the non-thrombogenicity was evaluated through incubation with platelet-rich plasma isolated from human whole blood. The water repellency was dramatically improved on the F-DLC-coated dual rough surface compared with that on DLC-coated Si or F-DLC-coated Si, which had a water contact angle of 130.6<SUP>o</SUP>. There was no significant difference in the values for the platelet-covered area between DLC-coated Si and the F-DLC-coated dual rough surface. As DLC is being considered for widespread clinical use as a surface coating for medical devices owing to its non-thrombogenicity compared with other biomaterials, the F-DLC-coated dual rough surface presented in this study still has the potential for clinical use, such as temporary blood-contacting medical devices, to take advantage of its high hydrophobicity.
Interaction fields based on incompatibility tensor in field theory of plasticity-Part I: Theory-
Hasebe, Tadashi Techno-Press 2009 Interaction and multiscale mechanics Vol.2 No.1
This paper proposes an interaction field concept based on the field theory of plasticity. Relative deformation between two arbitrary scales, e.g., macro and micro fields, is defined which can be implemented in the crystal plasticity-based constitutive framework. Differential geometrical quantities responsible for describing dislocations and defects in the interaction field are obtained, based on which dislocation density and incompatibility tensors are further derived. It is shown that the explicit interaction exists in the curvature or incompatibility tensor field, whereas no interaction in the torsion or dislocation density tensor field. General expressions of the interaction fields over multiple scales with more than three scale levels are derived and implemented into the present constitutive equation.
Hasebe, Tadashi Techno-Press 2009 Interaction and multiscale mechanics Vol.2 No.1
The theoretical framework of the interaction fields for multiple scales based on field theory is applied to one-dimensional problem mimicking dislocation substructure sensitive intra-granular inhomogeneity evolution under fatigue of Cu-added steels. Three distinct scale levels corresponding respectively to the orders of (A)dislocation substructures, (B)grain size and (C)grain aggregates are set-up based on FE-RKPM (reproducing kernel particle method) based interpolated strain distribution to obtain the incompatibility term in the interaction field. Comparisons between analytical conditions with and without the interaction, and that among different cell size in the scale A are simulated. The effect of interaction field on the B-scale field evolution is extensively examined. Finer and larger fluctuation is demonstrated to be obtained by taking account of the field interactions. Finer cell size exhibits larger field fluctuation whereas the coarse cell size yields negligible interaction effects.
Finite element analysis of 2D turbulent flows using the logarithmic form of the k-ε model
Hiroshi Hasebe,Takashi Nomura 한국풍공학회 2009 Wind and Structures, An International Journal (WAS Vol.12 No.1
The logarithmic form for turbulent flow analysis guarantees the positivity of the turbulence variables as k and ε of the k-ε model by using the natural logarithm of these variables. In the present study, the logarithmic form is incorporated into the finite element solution procedure for the unsteady turbulent flow analysis. A backward facing step flow using the standard k-ε model and a flow around a 2D square cylinder using the modified k-ε model (the Kato-Launder model) are simulated. These results show that the logarithmic form effectively keeps adequate balance of turbulence variables and makes the analysis stable during transient or unsteady processes.