• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2005.11a
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• pp.100-105
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• 2005

In this paper, a small supersonic wind tunnel is designed and built to study the flow characteristics of a supersonic impulse turbine cascade. The flow is visualized by means of a single pass Schlieren system. The supersonic cascade with 2-dimensional supersonic nozzle is tested for various gaps between the nozzle and cascade. By the experiment, the flow is visualized and static pressure of the cascade was measured. And highly complicated flow patterns including shocks, nozzle-cascade interaction and shock boundary layer interactions, flow characteristics of the supersonic turbine are observed.

• The KIPS Transactions:PartB
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• v.12B no.5 s.101
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• pp.535-542
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• 2005

Amplified Collaboration Environment(ACE) is a display-rich project room that enables distributed teams to intensively work together to solve a complex problem. This paper presents reviews of some most important shared workspace models in real-time collaboration systems. It then describes a set of iterative design studies of evaluation the shared workspace for ACEs. The study involved small groups of users in two ACEs performed a collaborative visualization and analysis task while varying the display technology configuration. The goal of this study was to enhance intensive collaborative work in ACEs. The results showed that the participants benefited from the ability to see others' work over the high-resolution shared workspace, which helped enhance group awareness and performance.

• Fire Science and Engineering
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• v.13 no.4
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• pp.30-37
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• 1999

In this study, reduced-scale experiments as the alternative to a real-scale fire test were conducted to understand fire properties in atrium space. The scaling laws were derived from $\pi$-parameters which were deduced by dimensional analysis of governing equations (continuity, conservation of momentum and conservation energy). The 1/50 scale experiment simulated the real-scale fire test in SIVANS atrium at Japan were conducted under the scaling laws. And this results were compared with real-scale experiment results. Furthermore these results were visualized by video recording system using laser light sheet.

• Journal of Energy Engineering
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• v.4 no.2
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• pp.261-269
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• 1995

본 연구에서는 밀폐형 2상 열사이폰의 액체 Pool에서 발생하는 핵비등현상과 유동영역에 대해 가시화 방법으로 연구하였다. 실험용 열사이폰은 스텐레스와 유리관을 이용하여 제작하였으며, 열공급은 증발부 주위에 설치된 유도 가열용 코일에 고주파를 가함으로써 스텐레스 외면에 발열이 일어나도록 하였다. 이에 따른 결과는 다음과 같다. 실험용 열사이폰은 고주파 가열등 열사이폰의 작동성능을 저해하는 여러 요인들이 포함되어 있었으나, 실험결과 이러한 문제는 실험 내용에 영향을 미칠만큼 크게 나타나지 않았다. 열속과 상당압력의 범위는 각각2$m^2$, 0.1

• Proceedings of the KAIS Fall Conference
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• 2009.05a
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• pp.539-542
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• 2009

본 연구은 자동차용 가솔린엔진에 장착되는 인젝터의 연료공급 특성에 대한 것으로, 4홀과 12홀 인젝터의 분무질량분포, 벽류 및 가시화 실험을 수행하였다. 분무질량분포 실험을 통하여 인젝터 별 분무특성을 파악하고, 벽류측정실험을 통하여 흡기포트내의 연료 Wetting 특성을 확인하였다. 가시화실험을 통하여 분사각과 분무특성을 비교 분석하였다. 4홀과 12홀 인젝터의 분무특성비교를 통한 각 인젝터의 연료공급 특성분석은 가솔린엔진 설계시 기초자료로 활용될 수 있을 것이다.

• Journal of the Korean earth science society
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• v.27 no.2
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• pp.177-187
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• 2006

Due to a lack of reproducibility and visibility of the conventional equipment for westerly wave simulation, it is difficult to have indoor experiments at high school that show the stream of Hadley cell. A modified improvement of the old one improves the problem. The side wall and bottom of the new equipment is made by copper and acrylic resin, respectively, in order to clarify the difference between the water temperature inside and outside of the water tank. The equipment also has a high quality digital record for generating exact analysis of the results. And we also carried out several experiments that relate theoretical and experimental aspection of westerly wave. Temperature Detected Sheet (TDS) in flow visualization unit provides not only visual information of liquid flow, but also clear understanding of the relation between upper and lower wind flow structure. And the liquid stream simulated in indoor experiment using proposed equipment is commensurate with westerly wave in real atmosphere. The efficiency of educational properties of the proposed equipment is verified indirectly by Likert Scales survey of high school teachers.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.39 no.11
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• pp.891-896
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• 2015

This experimental study investigated the wake flow around an elastically supported circular cylinder. In this study, the Reynolds numbers are varied in the region of $1.4{\times}10^4{\leq}Re{\leq}3.2{\times}10^4$. Under these conditions, we have captured the process of the wake mechanism and the moving path of the vortex by measuring the velocity at each position in the wake around the cylinder. Further, these facts from the wind tunnel test are proved by a flow visualization test through a water channel. From the result, we have arrived at the following conclusions : i) The process (formation${\rightarrow}$growth${\rightarrow}$collapse) of vortex is observed in the wake around the cylinder, ii) The vortex efflux angle is approximately $16^{\circ}{\sim}17^{\circ}$ under the experimental conditions. These angles have no relationship with the velocity change and the existence of flow-induced vibrations of the cylinder, and iii) The moving path of the vortex center is obtained by spectrum analysis of the fluctuating velocity behind the cylinder. These are confirmed by conducting visualization tests.

• 대한공업교육학회지
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• v.32 no.2
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• pp.87-103
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• 2007

The purpose of this study was to develop of the smoke flow visualization device of learning wind tunnel, teaching-learning materials in order to demonstrate air-flow around the fluid-flow field qualitatively and understand the resistance concepts of fluid-flow in secondary school. The contents of this study were consisted of the development and experiment of smoke flow visualization for learning wind tunnel. The main results of this study were as follows: First, this developed teaching-learning material here will help students understand the fundamental physical phenomena related with the resistance of fluid and the various patterns of air-flow in the field of transportation technology. Second, flow visualization has shown the same tendency in both of theoretical and experimental patterns. Third, the airfoil model has the smallest wake region meaning resistance against air-flow of circular cylinder and square rod model. Forth, flow separation point at leading edge and wide wake region began to show under the angle of attack of airfoil model ${\alpha}$ is $20^{\circ}$. Fifth, the wake width of the flow field behind a golf ball with dimple became slightly narrower than that without dimple. Sixth, the developed device was made to apply the teaching and learning materials for the experiment and practice in order to increase students' interest and attitude.

• Journal of Biomedical Engineering Research
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• v.20 no.3
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• pp.283-290
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• 1999

Because MR(Magnetic Resonance) slice images have much information of functions about body organs, it is very effeclive for diagnoses lo analyze and visualize MR slice images. A visuahzation process is composed of medical image acquisition, preprocessmg, segmentation, inlerpolation, rendering. Segmentation and interpolation among thenl ,1re currenl hot topics because of MR slice image imperfections. This paper proposes a method for segmentalion, mlerpolation respectively and addresses 3 D-visualizmg of a head. We segmented head tissues uomg otructural knowledge of head studied by clinical experiments sequentially. We improved the dynamic elastic inlerpolation to Utilize in concave conlour. We compared the proposed segmentation method and the interpolation method with other methods.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• v.y2005m4
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• pp.349-354
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• 2005

In this paper, a small supersonic wind tunnel is designed and built to study the flow characteristics of a supersonic impulse turbine cascade. The flow is visualized by means of a single pass Schlieren system. The supersonic cascade with 2-dimensional supersonic nozzle was tested for various blade leading edge shapes and gaps between the nozzle and cascade. Highly complicated flow patterns including shocks, nozzle-cascade interaction and shock boundary layer interactions are observed.