• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.1057-1062
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• 2007

The purpose of this study is to find out design parameters of vibrating screen, such as particles motion, specific gravity, shape, and kinetic friction. In order to approach this problem, four materials of construction wastes, wood, styrofoam, concrete, and sand are used for dynamic modeling. To present friction between the particles material and tilt plates material, these particles model is applied in order to verify effectively. Generally, the vibrating screen is composed of three assemblies such as screen, wastes guide, supported of screen. This model regards vibrator as system of screen fixed tilt plates. The model is analyzed to present what kind of particles motion while the system is vibrating. and this vibration system has been implemented in a ADAMS dynamaic program. This modeling is consist of dynamic model separation state on particle size. This study make good technique to verify in theory.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2011년도 제37회 추계학술대회논문집
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• pp.666-669
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• 2011

이중펄스 로켓모타에 적용되는 격벽형 펄스분리장치의 파열판 형상을 변경하는 설계를 진행하였다. 펄스분리장치 설계 확정에 앞서 3가지 다른 형상의 파열판 평판시험을 진행하여 파열판 성능을 확인하였다. 평판시험후 시험결과를 분석하여 펄스분리장치 파열판의 8개의 원형 구멍형과 8개의 사다리꼴 구멍 형상을 적용하기로 결정하였다.

• 한국세라믹학회지
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• 제23권5호
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• pp.93-101
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• 1986

Microporous glasses were prepared from the 50 $SiO_2-44$ $B_2O_3-6$ $Na_2O$(wt%) parent glass by the phase eparation technique and were characterized by SEM, BET, and Gas Adsorption methods to investigate the possiblity of their use as salt-rejection membranes for reverse osmosis. The conditions of the phase separation for the possible glass membranes were optimized for the given parent glass. The temperature and duration of heat-treatment were desired to be lower(853K) and shorter (1/2~1 hr) respectively. The specific surface areas of porous glasses prepared in this study were about 80~120$m^2$/g and their pore size distribution had a unimodal shape(peak pore radius less than 15$\AA$) It was suggested that the porous glass obtained in this work could be effective for salt-rejection in point of pore size distributions but the way to increase its surface area for the high flux must be studied.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2008년도 춘계학술대회논문집
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• pp.185-188
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• 2008

In this study, we experimentally investigated that the optimization of pulsating jet to reduce the separated flow region behind the vertical fence. The vertical fence was submerged in the turbulent boundary layer in the circulating water channel and we applied phase averaged PIV method to measure the instantaneous velocity fields around the fence. One cycle of pulsating jet is divided into 20 phases and grabbed total 200 instantaneous velocity fields at each phase. The experiments were performed by varying the frequency, maximum jet velocity and the shape of pulsating jet wave. Pulsating jet was precisely made by piston-type pump controlled by the computer. The obtained results were compared with normal fence flow. From this study, we found there is the specific frequency which is effective in reducing the reattachment region.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 춘계학술대회논문집B
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• pp.502-507
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• 2000

Fundamental studies on the drag reduction of the circular cylinder having dimple were conducted by the measurement of the fluid force acting on the cylinder and by the flow visualization around the cylinder. The drag coefficients were changed by the shape and the space for the arrangement of the dimple. The drag of the cylinder was reduced about 50% by the proper arrangement of the dimple. The flowfield around the cylinder having dimple, which was the minimum drag, was visualized by the hydrogen bubble technique. In this case, the separation points were moved rearward and the wake region was small in comparison with the cylinder having no dimple.

• 한국유체기계학회 논문집
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• 제4권2호
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• pp.35-43
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• 2001

The flow characteristics passing a multi-point Pitot tube flow-meter of diamond shape and the characteristics of flow coefficients of the flow-meter are experimentally studied by varying combination of upstream rectangular dual elbows. The results provide the flow coefficients, which show good stability and reliability within the Reynolds number range coveted here in this study, and which can be used to measure flow-rates in practice. The variation of dual elbows upstream can change the velocity field so much that the flow pattern might thwart the precise flow measurement using the multi-point Pitot tube. The strongest swirl is detected in the case of $90^{\circ}$ dual elbow combination of all. In addition, it is observed that flow separation remains unchanged and occurs at the same point irrespective of various upstream dual elbow combinations.

• 한국자동차공학회논문집
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• 제5권3호
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• pp.35-46
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• 1997

In order to satisfy customer's requirements of ride comfort and high performance, it is necessary for designers to fully understand vehicle aerodynamics and wind noise of newly produced cars because characteristics of flow and wind noise are heavily dependent on each other. In this study numerical and experimental study have been carried out to analyse the effect of flow characteristics at around of rear view mirror on wind noise and soiling on the front S/W. As a result, it's found that the spiral flow mear the front pillar is weakened and spreaded because rear view mirror obstructs the flow. It is also shown that there is abrupt change of gradient of separa- tion line, separation area, intensity of spiral flow and turbulent kinetic energy with varying shape of neck and housing of rear view mirror.

• KSBB Journal
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• 제16권2호
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• pp.115-122
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• 2001

Molecular imprinting has now been established as a technique which allows the creation of tailor-made binding sites for many classes of compounds. MIPs were prepared by covalent and non-covalent chemical bonding systems, by interactions between functional monomer and template. The shape of MIP is divided to particle and membrane. MIP membranes can be prepared by surface imprinting, in-situ polymerization, wet phase inversion and the dry phase inversion method. MIPs have been mainly used for analytical separation and biosensor systems to separate and detect chiral compounds and materials with similar structures. However the application of MIP by the chemical industries is still in its infancy stages. This review summarizes the preparative characteristics and applications of MIP with respect to chiral separations and biosensors.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2001년도 춘계학술대회 논문집
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• pp.129-134
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• 2001

The drag reduction of the cylinder having square dimpled surface was studied by the measuring the drag force acting on the cylinder. The level of the drag reduction was changed by the arrangement shape of the square grooves and Reynolds number. The drag of the cylinder was reduced about 28% with proper arrangement of square grooves. The flow field around the cylinder having grooves at the minimum drag was visualized by using post color ink in order to see the influence of the grooves. In this case, the separation points were sifted rearward and the wake region was smaller than that of the smooth cylinder.

• Journal of Advanced Marine Engineering and Technology
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• 제26권2호
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• pp.233-239
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• 2002

The drag reduction of the cylinder having square dimpled surface was studied by the measuring the drag force acting on the cylinder. The level of the drag reduction was changed by the arrangement shape of the square grooves and Reynolds number. The drag of the cylinder was reduced about 28% with proper arrangement of square grooves. The flow field around the cylinder having grooves at the minimum drag was visualized by using post color ink in order to see the influence of the grooves. In this case, the separation points were silted rearward and the wake region was smaller than that of the smooth cylinder.