• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1999년도 춘계학술대회 논문집
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• pp.111-116
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• 1999

Over the last few years, there has been a growing interest in quantitative representation of heat transfer and fluid flow phenomena in weld pools in order to relate the processing conditions to the quality of the weldment produced and to use this information for the optimization and robotization of the welding process. Normally, a theoretical model offers a powerful alternative to estimate the important input parameters and to calculate the effects of varying any of parameters. To solve this problem, a transient 2D(two-dimensional) heat conduction and a transient 2D axisymmetric heat and fluid model were developed for determining weld bead geometry and temperature distribution for the GMA(Gas Metal Arc) welding process. The equation was solved using a general thermofluid-mechanics computer program, PHOENICS code, which is based on the SIMPLE algorithm. The simulation results showed that the calculated bead geometry from two developed models reasonably agree with the experiment result.

• 한국가스학회지
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• 제5권2호
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• pp.52-61
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• 2001

[ $100,000m^3$ ] 규모의 원통형 탱크에 저장되어 있는 초저온의 액화천연가스는 외부조건 및 운전모드에 따라 복잡한 유동양상과 열물성 변화를 보인다. 이런 현상은 LNG의 저장 및 운전조건과 탱크의 설계사양 및 열전달 특성에 크게 영향을 받으며, 또한 저장탱크내 LNG의 안정적 저장 및 공급에 영향을 미치게 된다. 따라서, 본 연구에서는 LNG 저장탱크의 외부조건에 따른 2차원 열전달 해석, 시운전시 초기 상온상태의 LNG 저장탱크를 냉각하기 위한 Cool Down 프로세스, 그리고 탱크내 LNG의 유입 및 상승을 고려한 주입프로 세스의 해석을 수행하였다. 또한, 혼합 LNG 저장에 대한 해석도 수행하였다. 이런 LNG저장탱크내의 전반적인 열유동에 대한 해석을 토대로 가시화된 종합적인 열유동 해석프로그램을 개발하였다. 본 프로그램의 개발은 탱크내 저장된 LNG의 열적 안정성 해석의 기술력 확보뿐만 아니라 실탱크의 기본설계에 이용할 수 있게 되었다.

• Nuclear Engineering and Technology
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• 제37권5호
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• pp.401-422
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• 2005

We review here research and development progress achieved in US Plasma Chamber technology roughly over the last decade. In particular, we focus on two major programs carried out in the US: the APEX project (1998-2003) and the US ITER TBM activities (2003-present). The APEX project grew out of the US fusion program emphasis in the late 1990s on more fundamental science and innovation. APEX was commissioned to investigate novel technology concepts for achieving high power density and high temperature reactor coolants. In particular, the idea of liquid walls and the related research is described here, with some detailed examples of liquid metal and molten salt magnetohydrodynamic and free surface effects on flow control and heat transfer. The ongoing US ITER Test Blanket Module (TBM) program is also described, where the current first wall/blanket concepts being considered are the dual coolant lead lithium concept and the solid breeder helium cooled concepts, both using ferritic steel structures. The research described for these concepts includes both thermofluid MHD issues for the liquid metal coolant in the DCLL, and thermomechanical issues for ceramic breeder packed pebble beds in the solid breeder concept. Finally, future directions for ongoing research in these areas are described.