통합 검색 | Korea Science

염금수;장근식
- 한국전산유체공학회:학술대회논문집
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- 한국전산유체공학회 2004년도 추계 학술대회논문집
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- pp.215-220
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- 2004
A mathematical formulation based on two-phase, two-fluid hyperbolic conservation laws is developed to investigate propagation of shock waves in one- and two-dimensions. We used a high resolution upwind scheme called the split-coefficient matrix method. Two extreme cases are computed for validation of the computer code: the states of a pure gas and a pure liquid. Computed results agreed well with the previous experimental and numerical results. It is studied how the shock wave propagation pattern is affected by the void fraction in the two-phase flow. The shock structure in a two-phase flow turned out, in fact, much deviated from the shape well known in the gas only phase.
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이정호;이부윤;전제영;이명렬;조종래
- 한국정밀공학회:학술대회논문집
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- 한국정밀공학회 1996년도 추계학술대회 논문집
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- pp.964-968
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- 1996
The demands of size and quality of large steel shaft forgings for ship building, power plant, steel plant, etc. are rapidly increasing, and some of these productions are manufactured from ingot weighing more than 300 tons. For use as rotating components. shafts require toughness, strength and homogeneity, and therefore are produced through a variety of heat treatments. According to the increase of ingot size, micro- and macrosegregation and also mass effect of the product increase. Thus, special care should be paid to the heat treatment of such large shaft forgings. In this paper, the heat treatment of large shaft forgings such as rotor and back-up roll is calculated using the commercial finite element code SYSWELD. Calculated distributions of temperature and phase are compared with experimental data. The continuous cooling transformation diagram, thermal and mechanical properites of each phase are used. The phase proportion, hardness and residual stress during water quenching are discussed.
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Ki, Tae-Kyung;Jeong, Sang-Kwon
- 한국초전도ㆍ저온공학회논문지
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- 제13권2호
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- pp.25-28
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- 2011
A compact phase controller of pulse tube refrigerator is proposed in this paper. Most pulse tube refrigerators available now consist of a long inertance tube and reservoir as the phase controller. The long inertance tube and reservoir present a challenge for compact packaging in some applications. To overcome this disadvantage, the long inertance tube and reservoir are replaced with the compact phase controller consisted of mass, spring and damper in pulse tube refrigerator. This process is achieved using similarity of mechanical, electrical, and acoustic system and the specific configuration of the compact phase controller is designed. From the simulation code in this paper, the performance of pulse tube refrigerator with the designed compact phase controller is confirmed to be comparable to pulse tube refrigerator with the long inertance tube and reservoir.
https://doi.org/10.9714/psac.2011.13.2.025 인용 PDF KSCI