http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
기계적합금화로 제조된 Ni-20Cr-20Fe-5Nb 합금에서 PCA로서 H<sub>2</sub>O의 역할과 시효석출거동
김일호,권숙인,이원식,채수원,황선근,김명호,Kim Il-Ho,Kwun S.I.,Lee Won-Sik,Chae S.W.,Hwang S.K.,Kim M.H. 한국분말야금학회 2006 한국분말재료학회지 (KPMI) Vol.13 No.3
The effect of use of $H_2O$ as PCA(process control agent) to prevent the carbon contamination during mechanical alloying process and the precipitation behavior in Ni-20Cr-20Fe-5Nb bulk alloy after aging were investigated. NbC and $Cr_2O_3$ were formed during mechanical alloying and consolidation processes in the Ni-20Cr-20Fe-5Nb alloy in which methanol($CH_3OH$) was added as PCA. Formation of NbC in this alloy decreased the amount of Nb dissolved in the Ni matrix. The use of $H_2O$ as PCA in Ni-20Cr-20Fe-5Nb alloy prevented the formation of NbC and increased the hardness. The increase of hardness in this alloy was attributed to the increased amount of Nb dissolved in the Ni matrix. After aging treatment for 20 hours at $600^{\circ}C\;and\;720^{\circ}C$ of Ni-20Cr-20Fe-5Nb bulk alloy in which $H_2O$ added as PCA, ${\gamma}"$$(Ni_3Nb,\;tetragonal)\;and\;{\delta}\;(Ni_3Nb,\;orthorhombic)$ precipitates were formed, respectively. The precipitation temperatures of ${\gamma}"$ and ${\delta}$ in this bulk alloy were lower than those in commercial IN 718 alloy. It seemed that the lower precipitation temperatures for ${\gamma}"$ and ${\delta}$ in this bulk alloy than in commercial IN 718 alloy were due to severe plastic deformation during mechanical alloying.
김명호(M.H.Kim),조경민(K.M.Cho),박심수(S.S.Park),허남건(N.K.Hur) 한국자동차공학회 1992 한국자동차공학회 춘 추계 학술대회 논문집 Vol.1992 No.11
The three-dimensional steady state flow field inside a typical dual-monolith automotive catalytic converter was simulated using STAR-CD. The monolith brick resistance coefficient was acquired from the comparison between the Ford experimental data of pipe flow with monolith and simulation results by STAR-CD. In this study, computation is conducted with the variation of inlet condition: straight inlet. 90° bend inlet. Therefore. the purpose of this study is to use multi-dimensional CFD code to simulate the flow field inside the converter. to complement comprehensive modeling efforts. and to provide a diagnostic tool for better converter design.
Myrinet 환경에서 예조건화 Navier-Stokes 코드의 병렬처리 성능
김명호(M.-H. Kim),이기수(G.S. Lee),최정열(J.-Y. Choi),김귀순(K.S. Kim),김성룡(S.-L. Kim),정인석(I.-S. Jeung) 한국전산유체공학회 2001 한국전산유체공학회 학술대회논문집 Vol.2001 No.-
Parallel performance of a Myrinet based PC-cluster was tested and compared with a conventional Fast-Ethernet system. A preconditioned Navier-Stokes code was parallelized with domain decomposition technique, and used for the parallel performance test. Speed-up ratio was examined as a major performance parameter depending on the number of processor and the network topology. As was expected, Myrinet system shows a superior parallel performance to the Fast-Ethernet system even with a single network adpater for a dual processor SMP machine. A test for the dependency on problem size also shows that network communication speed is a crucial factor for parallelized computational fluid dynamics analysis and the Myrinet system is a plausible candidate for high performance parallel computing system.