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The Application of CFD for Ship Design
김우전(Wu-Joan Kim),반석호(Suak-Ho Van) 한국전산유체공학회 2003 한국전산유체공학회지 Vol.8 No.2
The issues associated with the application of CFD for ship design are addressed. Doubtlessly at the moment, CFD tools are very useful in evaluating hull forms prior to traditional towing tank tests. However, time-consuming pre-processing is an obstacle in the daily application of CFD tools to improve hull forms. The accuracy of computational modeling without sacrificing the usability of CFD system is also to be assessed. The wave generation is still predicted by using potential panel methods, while velocity profiles entering into propeller plane is solved using turbulent flow solvers. The choice of turbulence model is a key to predict nominal wake distribution within acceptable accuracy. The experimental data for CFD validation are invaluable to improve physical and numerical modeling. Other applications of CFD for ship design than hull form improvement are also given. It is certain that CFD can be a cost-effective tool for the design of new and better ships.
분말야금법으로 제조된 2124AI 합금의 빠른변형률속도 초소성 거동
金祐塡,張勝彦,南勝義,金亨駿 弘益大學校 科學基術硏究所 1999 科學技術硏究論文集 Vol.10 No.2
Ceramic whisker or particulate reinforced aluminum based metal matrix composites show high room temperature strength, but their low formability makes it difficult to form into desired shapes. By superplastic deformation, their formability can be improved and it is possible to produce complex parts for automotive aerospace simultaneously instead of many near-net-shape forming operations. This study has been carried out to investigate the high temperature mechanical and superplastic properties in 2124Al alloy. SRC(Strain Rate Change) tests show that the value of n(stress exponent) is around 3 at high strain rate and above 5 at low strain rate. It was turned out that 212Al matrix alloy exhibited reasonably high tensile elongation above 250% with the broad range of temperature and strain rate. Especially, at 550℃, both materials showed very high elongation failure up to 700% for 2124Al alloy. The strength comparison is lower strength then 2124Al composites were obtained that the composite is lower strength than 2124Al alloy at superplastic region.