• Title/Summary/Keyword: 경계 특성

Search Result 2,878, Processing Time 0.031 seconds

Numerical Analysis of Natural Convection inside Spray Coating Room on Temperature Distributions (자연대류를 고려한 스프레이 코팅 룸에서의 온도분포 해석)

  • Kim, Nam Woong;Kim, Bo-Seon;Kim, Kug Weon
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.20 no.8
    • /
    • pp.425-430
    • /
    • 2019
  • Zinc coatings are widely used because of their environmental friendliness and high performance. In general, the coating temperature is a major factor in determining the coating layer thickness and coating quality. In the case of a zinc coating, a uniform and appropriate coating temperature is required. In this study, a thermal flow simulation of the air flow was performed to analyze the temperature distribution of a zinc spray coating room in a natural convection state. Using SolidWorks, modeling was performed for two spray coating rooms, a preheating room, and a drying room, and a thermal flow coupled analysis was performed using ANSYS-FLUENT. As a result of the analysis, the temperature distribution characteristics in the spray coating rooms were determined. It was found that the present temperature was below the target temperature of $25^{\circ}C$. Simulations were conducted for two different boundary conditions (one with a heater added and another with the open part closed). The simulation results show that the method of closing the open part is better than adding the heater.

A study on the characteristics of Judith Clark's fashion exhibitions (주디스 클락의 패션 전시에 나타난 연출 특성)

  • Kim, Ji Yul;Ma, Jin Joo
    • The Research Journal of the Costume Culture
    • /
    • v.27 no.4
    • /
    • pp.310-322
    • /
    • 2019
  • Since the late 2000s, fashion exhibitions have expanded to encompass a variety of concepts and sizes, and the need for research on exhibition planning, installation, and direction, including curating, is emerging. In this context, basic research is deemed necessary to encourage more experimental and in-depth research into the planning and orientation of domestic fashion exhibitions. Accordingly, by analyzing the exhibitions of Judith Clark, a pioneering fashion curator, and fashion exhibition planner, the aim of this study is to examine the characteristics and directing points of her curation. This study proceeds as follows: first, the concept and type of fashion exhibition and curation are investigated. Second, the exhibition cases curated or produced and installed by Judith Clark are examined and analyzed. Finally, based on this analysis, the characteristics and directing points of her curation are identified. In exhibitions, Clark's directing style features use of a variety of objects, the diversification of the flow-path through space division, and collaborations with various fields or experts. Clark's curation points, based on such characteristics, are as follows: reproduction-oriented curation to capture the age of the time based on historical research; storytelling-based curation; and transboundary curation with multiple methods and open processes. This study is expected to serve as a foundation and precedent that will lead to further research on fashion exhibitions and implementation.

Evaluation on Applicability of Finite Element Analysis in Model Test of Pile Pullout (말뚝 인발모형실험에 대한 유한요소해석의 적용성 평가)

  • You, Seung-Kyong;Shin, Heesoo;Lee, Kwang-Wu;Park, Jeong-Jun;Choi, Choong-Lak;Hong, Gigwon
    • Journal of the Korean Geosynthetics Society
    • /
    • v.18 no.2
    • /
    • pp.11-21
    • /
    • 2019
  • This paper describes the applicability of FEA(Finite Element Analysis) to the simulation of pile pullout behavior under various soil conditions (relative density and fines content), in order to evaluate reasonably the pullout resistance of pile. That is, the results of previous research (You et al., 2018) were analyzed by FEA under the same conditions. The FEA results showed that axisymmetric analysis using virtual ground was able to evaluate the skin friction of the pile. Also, axisymmetric analysis, which can apply the shear resistance characteristics of the pile-soil interface in various soil conditions, could be used as an analytical method that can simulate a reasonable pile pullout behavior. Therefore, the analytical model proposed in this study was able to simulate appropriately the pullout behavior based on the stress-strain relationship of the pile-soil interface.

Evaluation of Adsorption Characteristics of 2-Picoline onto Sylopute (실로퓨트에 대한 2-피콜린의 흡착 특성 평가)

  • Yang, Ji-Won;Kim, Jin-Hyun
    • Korean Chemical Engineering Research
    • /
    • v.57 no.2
    • /
    • pp.210-218
    • /
    • 2019
  • Batch experiment studies were carried out on the adsorption of the major tar compound, 2-picoline, derived from the plant cell cultures of Taxus chinensis, using Sylopute while varying parameters such as initial 2-picoline concentration, contact time and adsorption temperature. The experimental data were fitted to the Langmuir, Freundlich, Temkin and Dubinin-Radushkevich isotherm models. Comparison of results revealed that the Langmuir isotherm model could account for the adsorption isotherm data with the highest accuracy among the four isotherm models considered. From the analysis of adsorption isotherms, it was found that adsorption capacity decreased with increasing temperature and the adsorption of 2-picoline onto Sylopute was favorable. The kinetic data were well described by the pseudo-second-order kinetic model, while intraparticle diffusion and boundary layer diffusion did not play a dominated role in 2-picoline adsorption according to the intraparticle diffusion model. Thermodynamic parameters revealed the exothermic, irreversible and non-spontaneous nature of adsorption. The isosteric heat of adsorption decreased as surface loading ($q_e$) increased, indicating a heterogeneous surface.

Jet Interaction Flow Analysis of Lateral Jet Controlled Interceptor Operating at Medium Altitude (중고도에서 운용되는 측 추력 제어 요격체에 대한 제트 간섭 유동 분석)

  • Choi, Kyungjun;Lee, Seonguk;Oh, Kwangseok;Kim, Chongam
    • Journal of the Korean Society for Aeronautical & Space Sciences
    • /
    • v.46 no.12
    • /
    • pp.986-993
    • /
    • 2018
  • Lateral thrust jet has better maneuverability performance than the control surface like the conventional fin for attitude control or orbital transition of guided weapons. However, in the supersonic region, a jet interaction flow occurs due to the lateral thrust jet during flight, and a complicated flow structure is exhibited by the interaction of the shock wave, boundary layer flow, and the vortex flow. Especially, hit-to-kill interceptors require precise control and maneuvering, so it is necessary to analyze the effect of jet interaction flow. Conventional jet interaction analyses were performed under low altitude conditions, but there are not many cases in the case of medium altitude condition, which has different flow characteristics. In this study, jet interaction flow analysis is performed on the lateral jet controlled interceptor operating at medium altitude. Based on the results, the structural characteristics of the flow field and the changes of aerodynamic coefficient are analyzed.

Conservation Treatment and Scientific Analysis of the Jade Excavated from the First Buried Place of King Jung-jo (정조(正祖) 초장지(初葬地) 출토 옥의 과학적 분석 및 보존처리)

  • Lee, Tae-jong;Oh, Jung-hyeon;Kim, Sa-dug;Lee, Jung-min
    • Korean Journal of Heritage: History & Science
    • /
    • v.46 no.4
    • /
    • pp.160-173
    • /
    • 2013
  • This research aims to understand the precise character of relics based on literature search and material analysis of the jade excavated from the first buried place of King Jung-jo, and to assess the level of damage through non-destructive diagnosis. Furthermore, scientific conservation treatment was used to restore the original shape of the excavated jade. According to literature search, the excavated jade is known to be jasper, but material analysis showed that it was as a serpentine with the mineral composition of antigorite. Infrared thermography analysis to assess deterioration showed that the internal damage is the result of the interstices developed along the boundary surface of the obtained jade. For conservation treatment of the damaged area on the surface, the jade was filled with a mixture of plaster and glue, and covered with a mixture of acrylic paint and gloss medium for protection, and color was adjusted.

Buckling Analysis of Laminated Composite Trapezoidal Corrugated Plates (적층 복합재료 사다리꼴 주름판의 좌굴해석)

  • Park, Kyung-Jo;Kim, Young-Wann
    • Composites Research
    • /
    • v.32 no.4
    • /
    • pp.185-190
    • /
    • 2019
  • This work investigates the elastic buckling characteristics of laminated composite trapezoidal corrugated plates with simply supported edges using the analytical method. In the analysis, three types of in-plane loading conditions: uniaxial, biaxial and shear loads are considered. Because it is very difficult to determine the mechanical behavior of 3-dimensional corrugated structures analytically, the equivalent homogenization model is adapted to investigate the overall mechanical behavior of corrugated plates. The corrugated element is homogenized as an orthotropic material. The previous formulae for bending rigidities of corrugated plate are adapted in this paper. The comparisons of the proposed analytical results with those of FEA based on the shell element are made to verify the proposed analytical method. In the comparison study both the critical buckling loads and the buckling mode shapes are presented. Some numerical results are presented to check the effect of the geometric properties.

Analysis of Isochrone Effect of Clayey Soils using Numerical Analysis (수치해석을 이용한 점성토 지반의 아이소크론 영향 분석)

  • Lee, Yun-Sic;Lee, Jong-Ho;Lee, Kang-Il
    • Journal of the Society of Disaster Information
    • /
    • v.15 no.1
    • /
    • pp.84-97
    • /
    • 2019
  • Purpose: The consolidation settlement of soft ground is dependent on the distribution of pore water pressure which is also affected by hydraulic conductivities (boundary condition) of layers, thickness of clayey soil layer and surcharge. Results: However, the current consolidation analyses are mostly based on Terzaghi's consolidation theory that assumes the initial pore water pressure ratio with depth to be constant. In this study, numerical analysis are carried out to investigate the variation of pore water pressure dissipation with depth and thickness of clayey soil layer, time, surcharge as well as drainage conditions. Conclusion: Comparative study with Terzaghi's consolidation theory is also conducted. The result shows that Terzaghi's consolidation theory should be used with caution unless it is ideally corresponded to the isochrone.

Drought Analysis Using the Low Flow Frequency and Computation Model of Maintenance Flow (갈수빈도와 정상유량산정 모델을 활용한 가뭄상황 분석)

  • Son, Kyung-Hwan;Oh, Sung-Ryul;Choi, Kyu-Hyun
    • Proceedings of the Korea Water Resources Association Conference
    • /
    • 2017.05a
    • /
    • pp.356-356
    • /
    • 2017
  • 최근 국토교통부 홍수통제소에서는 가뭄대응을 위해 1, 3개월 갈수예보를 시범적으로 운영하고 있다. 국가재난 위기경보단계(관심, 주의, 경계, 심각)에 따라 분류된 기준유량과 예측유량의 비교를 통해 갈수상황을 판단하며, 그 중 기준유량은 일본의 정상유량 산정 기법에 의해 계산된다. 그러나 우기 건기에 따라 상이한 유입량 및 물 사용량이 정상유량 산정에 고려되지 않았고, 각 위기단계별 물 부족상황이 재현되지 못하였다. 또한, 하천유량 부족은 가뭄과 관계가 밀접함에도 불구하고, 가뭄상황과의 연계분석이 이뤄지지 않았다. 본 연구에서는 갈수빈도와 정상유량산정 모델을 이용하여 기준유량을 재설정하고 가뭄상황을 분석하였다. 대상유역은 영산강유역으로 선정하였고, 보고된 하천수사용허가량, 댐 용수 공급량 및 10년 이상 장기간 관측된 관측소별 일 유량자료를 활용하였다. 일 관측유량을 7일 이동평균으로 변환한 후, 유황분석을 통해 $Q_{90}$을 산정하였으며, 빈도별 $Q_{90}$을 계산하였다. 정상유량 산정 모델에서 입력 자료(자연유량, 댐 공급량 및 하천수 허가량)에 가중치를 두어 양을 조절하고 각 빈도에 맞는 관개기 및 비관개기 기준유량을 산정 하였다. 가뭄지수로는 국내 활용성이 높은 Standardized Precipitaion Index (SPI) 및 Standardized Runoff Index (SRI)를 선정하였고, 이를 지속기간 1, 3, 6, 12개월에 따라 일별로 계산하였다. 7일 평균 관측유량이 기준유량 이하일 때, 이시점을 전 후로 가뭄지수의 시공간적 특성과 가뭄의 지속기간 및 심도를 분석하여 가뭄상황을 제시하였다. 본 연구의 결과는 갈수예보 시 하천유량 부족에 따른 물수지 및 가뭄상황에 대한 직관적인 판단과 갈수기 효율적인 하천수 조정 협의에 기여할 것으로 본다.

  • PDF

Simulation Study of Capacitively Coupled Oxygen Plasma with Plasma Chemistry including Detailed Electron Impact Reactions (전자충격반응을 포함하는 플라즈마 화학반응을 고려한 용량결합형 산소플라즈마의 전산모사 연구)

  • Kim, Heon Chang
    • Applied Chemistry for Engineering
    • /
    • v.22 no.6
    • /
    • pp.711-717
    • /
    • 2011
  • Two dimensional simulation results of a capacitively coupled oxygen plasma in a cylindrical reactor geometry are presented. Detailed electron impact reaction rates, which strongly depend on electron energy, are computed from collision cross sections of electrons with $O_2$ and O. Through the coupling of a three moment plasma model with a neutral chemistry/transport model are predicted spatiotemporal distributions of both charged species (electron, $O_2{^+}$, $O^+$, $O_2{^-}$, and $O^-$) and neutral species including ground states ($O_2$ and O) and metastables, known to play important roles in oxygen plasma, such as $O_2(a^1{\Delta}_g)$, $O_2(b^1{{\Sigma}_g}^+)$, $O(^1D)$, and $O(^1S)$. The simulation results clearly verify the existence of a double layer near sheath boundaries in the electronegative plasma.