• 한국자동차공학회논문집
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• 제7권7호
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• pp.24-31
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• 1999

The MPI engine becomes increasingly popular because it meets two requirements of stringent pollutant emission and the lower fuel consumption. Even though supplies the same amount of fuel to each cylinder , it is hard to precisely control the air-duel ration due to the different amount of air flowing into each cylinder. The uniformity of air-fuel ration in each cylinder is considerably affected by the plenum chamber configuration . This study is focused on experimentally analyzing the flow characteristics within the plenum chamber In the present experiment , steady and valve dynamic state flow tests are performed and the flow field inside the plenum chamber is visualized and measured by utilizing a laser sheet visualization technique and a PTV method. These measured results indicate that the flow structure in the plenum chamber is highly influenced by the plenum chamber configurations, suction flow rates, crank speeds and so on.

• 보존과학회지
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• 제22권
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• pp.5-14
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• 2008

본 연구에서는 박물관 내장재료, 유물포장시 사용되는 포장재료에서 나오는 실내대기오염물질로 챔버 테스트 및 오디 테스트를 실시하였다. 오디 테스트 결과 금속에 따라서 목재나 시멘트에 의해 부식되는 형태가 다르게 나타난다는 것을 알 수 있었으며, 금속의 부식에 가장 많은 영향을 미친 목질제품은 18T HS(E0)와 9mm합판(F0,E0)이었으며, 시멘트는 6개월이 지난 시멘트였다. 유해가스 챔버 테스트 결과 대부분의 시편에서 부식이 관찰되었으며, 특히 포름산, 아세트산, 아세트알데히드에서 철, 구리, 청동시편의 부식이 심각하게 진행되었다. 포장재의 폭로실험에서는 저습의 조건에서 표면적으로 큰 변화가 나타나지 않으나, 고습의 조건에서는 금속 시편이 변색되거나 부식되는 현상이 나타났다.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2017년도 제48회 춘계학술대회논문집
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• pp.112-115
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• 2017

고공엔진시험설비에서 지상 시험 조건의 시험 가능 여부와 설비 안전 문제를 점검하고자 로켓 엔진 유동을 해석하였다. 진공 챔버를 개방한 상태에서 냉각수를 초음속 디퓨저로 분사하면서 엔진이 작동하는 상황이며, 2차원 축대칭과 플룸, 공기, 냉각수의 3원 혼합물로 가정하였다. 해석 결과 냉각수 유량 200 kg/sec까지 지상 조건 시험이 가능하였다. 그러나 시동 초기 플룸의 역류로 인해 진공 챔버가 고온에 노출되고, 동시에 냉각수 역류로 인해 진공 챔버 내부가 오염되었다. 따라서 충분한 단열 대책과 오염 회피를 위한 작업이 선행되어야 한다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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• pp.73-76
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• 1997

The temperature control system for semiconductor test handler is designed. We controlled the temperature of chamber using 3-wire RTD sensor and MVME EMbedded controller. VxWorks that is a real-time operating system is used and heater is controlled by PWM. Temperature fluctuation of chamber is decreased within 0.3.deg. C, which is about one-half of that of commercial controller.

• 한국안전학회지
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• 제8권4호
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• pp.107-113
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• 1993

Small rectangular explosion chamber of its size 25cmX25cmX32cm with a circular bursting diaphram at the top was used to study the mechanism of gas explosion to fire transition phenomena, the process of ignition of solid combustibles during a gas explosion. To visulize the explosion to fire transition phenomena, transparent acryl window and high speed camera system were used. The test piece of solid combustible in this experiments was a 5cm$\times$5cm square sheet of newspaper which was placed in the explosion chamber filled with a LPG-air mixture. The mixture was ignited by an electric spark at the center of the chamber. Explosion to fire transition phenomena and the behavior of out flow and in flow of gas through the opening yielded by bursting the diaphram was visualized with shlieren system and without shlieren system. Diameter of a bursting dlaphram at the top of the explosion chamber was varied 5cm, 10cm, and 15cm, and the position of test piece were varied with 6 point. Explosion pressure was measured with strain type pressure transducer, and the weight difference of the test piece before and after each experimental run was measured. By comparing the weight difference of solid combustibles before and after the experiment and the behavior of out flow and inflow of gas after explosion, it was found that the possibility of ignition was depends on the LPG-air mixture concentration and the exposure period of test piece to the burnt gas. Test result of this experiments it was found that the main factor of this phenomena are that heat transfer to the test piece, and the pyrolysis reaction of test piece. Based on the results, the mechanism of the explosion to fire transition phenomena were inferred ; gas explosion- heat transfer to solid combustibiles ; pyrolysis reaction of solid combutibles : air inflow ; mixing of the pyroly gas with air ignition.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2000년도 연약지반처리위원회 학술세미나
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• pp.42-58
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• 2000

본 연구의 목적은 연약지반의 압밀계수 측정에 있어 Piezocone 관입시험을 이용할 때 관입시험자체의 정확성과 시험결과들에 미치는 여러 가지 지반공학적 영향요소들을 고려하려는데 있다. 본 연구의 연구실험방법으로는, Piezocone 관입을 위한 연약모형지반 조성을 위하여 초대형 Slurry Consolidometer에 Free Stress 상태의 Slurry를 45일간 압밀시킨 후 Automatic Computer Control Calibration Chamber (LSU/CALCHAS; Louisiana State University Calibration Chamber System)에 옮긴후 다시한번 압밀시키는 Two-Stage Consolidation Method를 사용하였다 동시에 연약모형지반내에 8개의 Piezometer를 설치하여 Piezocone 관입시 유발되는 지반 내에서의 과잉간극수압의 변환을 측정하였다. 총 25개의 Piezocone 시험중 4개는 Standard 10$\textrm{cm}^2$ Piezocone이고, 나머지 21개는 Miniature Piezocone이 사용되었다. 모형지반은 여러 가지 Boundary Condition들과 Stress Condition 그리고 Stress History등을 고려하여 조성되었다. 또한 Dissipation Test직후의 압밀특성을 확인하기 위하여 0.01초당 한 개이상의 실측점을 측정할 수 있는 Digital-Oscilloscope를 이용하였다. 특히 Dissipation Test, 즉시 Piezocone의 Filter Element에 잡히지 않는 과잉간극수압의 Initial Drop 존재에 관한 기존의 추측을 실제 실험치로 확인할 수 있었다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 추계학술대회논문집B
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• pp.520-525
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• 2000

This research is to analyze the ventilation performance of mechanical ventilation systems for indoor air quality control and management. A ventilation performance with supply sites is evaluated in a test model chamber and office room. A $CO_2$ gas as a tracer gas is used to measure the ventilation performance. The ventilation performance is found to increase with increased the ventilation rate. The ventilation performance is analysed with 55% at the supply air of 570 lpm and with 20% at the supply air of 100 lpm in a test chamber. The ventilation performance is better than 15% comparing with natural decay at the supply of 570 lpm in office room.

• 설비공학논문집
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• 제18권7호
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• pp.563-570
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• 2006

We investigated the emission characteristics of gaseous organic contaminants from building materials and newly constructed apartments. The emission test for building materials was done with small chamber method, and field measurements in newly constructed apartment were carried out by Korea Standard Test Method for Indoor Air Quality. First, the emission test by small chamber showed that the TVOC emission from building materials was much higher than formaldehyde. On the other hand, as expected, considerably high concentration of both TVOC and HCHO was detected in the new apartment.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2002년도 봄 학술발표회 논문집
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• pp.397-404
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• 2002

The bearing capacity of open-ended piles is affected by the degree of soil plugging, which is quantified by the IFR. There is not at present a design criterion for open-ended piles that explicitly considers the effect of IFR on pile load capacity In order to investigate this effect, model pile load tests using a calibration chamber were conducted on instrumented open-ended piles. The results of these tests show that the IFR increases with increasing relative density and increasing horizontal stress of soils. The unit base and shaft resistances decrease with increasing IFR. Based on the results of the model pile tests, new empirical relations for base load capacity and shaft load capacity of open-ended piles are proposed. In order to check the accuracy of predictions made with the proposed equations, the equations were applied to the full-scale pile load test preformed in this study, Based on the comparisons with the pile load test results, the proposed equations appear to produce satisfactory predictions.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2005년도 제24회 춘계학술대회논문집
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• pp.313-317
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• 2005

The facility improvement for hot firing test of combustion chamber having thrust of 30-tonf class and chamber pressure of 60bara were performed at ReTF in KARI. The KSR-III main engine having combustion pressure of 13bara and thrust of 12.5tonf had been successfully tested in this facility. To increase the capability of the facility, the feeding and the trust measurement system have been modified. The modification of the feeding system plays also a role of ensuring the stability of propellant supply and two step ignition sequence of combustion chamber. The one-axis thrust measurement system of up to 60tons has been newly manufactured and installed in test stand and the water/kerosene supply lines with high pressure vessel of $4m^3$ and gas nitrogen vessel of $10m^3$ have been designed for regenerative cooling system. The results of cold flow test show that this facility has been successfully improved to satisfy the requirement for hot firing test of high performance combustor.