• Journal of computational fluids engineering
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• v.9 no.3
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• pp.49-56
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• 2004

A heated and expanded helium is used to pressurize liquid propellants in propellant tanks of propulsion system of liquid propellant launch vehicles. To produce a heated and expanded helium, an hot-gas heat exchanger is used by utilizing heat source from an exhausted gas, which was generated in a gas generator to operate turbine of turbo-pump and dumped out through an exhaust duct of engine. Both experimental and numerical approaches of hot-gas heat exchanger design were conducted in the present study. Experimentally, siliconites - electrical resistance types - were used to simulate the full heat condition instead of an exhausted gas. Cryogenic heat exchangers, which were immersed in a liquid nitrogen pool, were used to feed cryogenic gaseous helium in a hot-gas heat exchanger. Numerical simulation was made using commercially utilized solver - Fluent V.6.0 - to validate experimental results. Helically coiled stainless steel pipe and stainless steel exhausted duct were consisted of tetrahedron unstructured mesh. Helium was a working fluid Inside helical heat coil and regarded as an ideal gas. Realizable k-』 turbulent modeling was adopted to take turbulent mixing effects in consideration. Comparisons between experimental results and numerical solutions are Presented. It is observed that a resulted hot-gas heat exchanger design is reliable based on the comparison of both results.

• Journal of the Korea Furniture Society
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• v.23 no.3
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• pp.229-241
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• 2012

Kuramata Shiro's design has been evaluated as an unseen type of beauty. He created totally different aesthetics from functional furniture by utilizing glass, acrylic, and expanded steel mesh which usually are inappropriate for making furniture. Kuramata told that his design always starts from zero status. By doing so, he could be free from the existing notion and form of furniture. This means that every function and every form must be based on his own understanding and experiment in order to produce newness. Owing to these efforts, we can regard his design as artworks. Kuramata tried to bring forth formative lines inside contour of furniture rather than to deform only the formal outlines of furniture. These lines are very delicate and sometimes ephemeral. But they establish formal potentiality of phenomenological being of beauty. Also those lines are built from humble industrial material but they open the truth of thing itself and introduce the beauty to field of aletheia. At the same time, transcending limitation of function and use, they leave pure form and temporariness. So, lines become a field of Heideggerian rift which produces embodiment of form. We can appreciate his design through these lines that are relatively thin but vivid enough to follow his original world of art.