• Journal of the Korean Society of Propulsion Engineers
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• v.25 no.1
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• pp.50-57
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• 2021

Engine cool down process is necessary for the liquid rocket engines using cryogenic propellants in order to meet the requirement of engine inlet temperature. This paper evaluates the cool down characteristics of oxidizer supply pipeline and engine in prechill process prior to the engine firing tests, and calculate the quantity of liquid oxygen consumption.

• Aerospace Engineering and Technology
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• v.6 no.2
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• pp.141-149
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• 2007

It was carried out hot-firing test with a regenerative-cooled sub-scale combustor which was applied regenerative-cooling, film cooling and thermal barrier coating. Test results showed that cooling methods used in the combustor play an full role in the operation of the combustor under the design condition but it is occurred high frequency combustion instability due to unsteady flow of fuel by structural support ring inserted in fuel manifold. The flow pattern of fuel was improved by excluding the ring and it will be carried out additional hot-firing test to verify the combustion stability of modified combustor.

• Journal of the KSME
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• v.57 no.11
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• pp.39-43
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• 2017

최근 정부의 친환경 에너지 정책에 따라 고효율 가스 복합 발전이 기존의 석탄 화력 복합 발전을 대체하는 추세에 있다. 발전용 가스터빈의 효율 향상에 따라 터빈 입구온도는 현재 $1,600^{\circ}C$에 이르러 가스터빈의 냉각 부하가 크게 증가되어 고온에서의 가스터빈 냉각 기술이 더욱 중요하게 되었다. 이 글에서는 고온에서 가스터빈 공기냉각 기구를 개발하고 냉각 성능 평가에 필요한 고온 풍동 시험설비 및 측정기술을 간략하게 소개하고자 한다.

• Journal of the Korean GEO-environmental Society
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• v.23 no.4
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• pp.11-20
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• 2022

In order to acquire hydraulic characteristics for unsaturated layers, water retention tests were performed and compared by using the evaporation method, volumetric pressure plate extractor (VPPE) and chilled-mirror dew point method. The evaporation and chilled-mirror method are currently developed experimental technology and measure the water retention curve of unsaturated soils quickly and accurately. In the evaporation and VPPE method, the water retention has been measured and compared until 100kPa matric suction and consequently the result of the evaporation method could be verified. In the chilled-mirror method, the water retention has been measured until high level of matric suction and the overall shape of water retention curves could be obtained. As a result of water retention tests, the representative water retention curves were obtained and the applicability of each test method was discussed. Using both the evaporation and chilled-mirror methods, the soil water retention curve can be acquired reasonably for the whole range of matric suction.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2006.05a
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• pp.100-109
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• 2006

In the regeneratively cooled combustion chambers using hydrocarbon fuels, coking occurs as the wall temperature increases which generates compounds deposition on the wall. This phenomenon reduces cooling capability of the coolant, finally it can cause damage to combustor by overheating of chamber wall. In this paper electrical heating equipment which is used for the coking experiments and the test results are introduced. The compatibilities of copper alloy with let A-1 were assessed at each condition based on the test results.

• The Korean Journal of Food And Nutrition
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• v.11 no.1
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• pp.6-10
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• 1998

It was determined to effects on cold test(CT) and smoke point (SP) of deodorizing temperature(DT) in corn oil. Increase of DT was induced to decrease of CT in deodorized oil, which was against the winterized oil inleted. Especially, the decrease of CT in deodorized oil was sharply at more than 26$0^{\circ}C$, this phenomenon was supposed to according the increase of total saturation degree as well as SU2, S2U, and S3 type triglyceride content. On the other hand, SP was showed the highest value as 242$^{\circ}C$ at DT as 24$0^{\circ}C$, the value was decreased to 235~238$^{\circ}C$ at DT as 245~27$0^{\circ}C$. This phenomenon was appeared in inverse proportion to the acid value of sample oils. Accordingly, high temperature deodorizing proved to be a very undesirable effect between general physicochemical characteristics, fatty acid composition and CT, SP etc.

• Journal of the Korean Society of Propulsion Engineers
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• v.11 no.3
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• pp.1-6
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• 2007

A 3-tonf-class high pressure sub-scale combustor was designed and manufactured to study the performance improvement of combustor. The combustor consists of a combustion chamber with film cooling, thermal barrier coating and water cooling channels to prevent thermal demage of the hardware and an injector head with 37 coaxial swirl injectors. Hot-firing tests were carried out at the design point with varying flow rate for film cooling. The test result revealed that the increase of film cooling flow rate decreases the combustion performance, but in the cases of similar film cooling flow rates, the combustion performance is dependent on the mixture ratio of main injector excluding the film cooling flow rate.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.2
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• pp.147-154
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• 2021

In this paper, the configuration and design of the test equipment are presented to examine the impact of rapid temperature change in cooling-air that may occur during the operation of the fixed wing aircraft Environmental Control System (ECS) on avionic electronic equipment. At the start of the ECS, the temperature of the air supplied by the aircraft ECS may be increased to 5.0℃ per second. In order to ensure operating of the avionic electronic equipment that is mounted on the aircraft and receives cooling-air from the ECS, testing equipment that can implement the cooling-air characteristic test environment is required. During design of test equipment was verified cooling-air rapid rate of temperature change by performing a thermal/flow analysis, performance of the test equipment implemented was verified by applying an avionic electronic equipment.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.05a
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• pp.25-28
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• 2010

The Cold flow and ignition tests have been performed for a technology demonstration model of 75-tonf liquid rocket engine thrust chamber which was designed and manufactured on the basis of the previous development experience of a 30-tonf liquid rocket engine thrust chamber. The hydrodynamic characteristics of the facility supply pipelines and the filling time of the cooling kerosene were obtained through the cold flow tests. The ignition cyclogram was determinded using the results and the ignition test was successfully carried out. The acquired data and test technique of present ignition test will be used in hot firing tests.

• Proceedings of the KIEE Conference
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• 2008.11a
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• pp.169-171
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• 2008

초전도케이블의 기술적 경제적 타당성에 대한 논의가 계속 진행되고 있는 가운데 이를 검증하기 위한 실계통 시험이 미국, 중국 및 일본을 포함한 주요 선진국들에서 이루어지고 있다. (1) 대용량 송전 및 절연성능 측면에서 장점을 가지고 있는 초전도케이블이 실제계통에서 적용한 예가 지금까지 많지 않은 이유는 막대한 초기투자 비용과 함께 신기술 도입에 따른 기술적 신뢰성 확보를 꼽을 수 있다. 특히 케이블 자체의 전기적 특성과 함께 냉각시스템의 신뢰성은 초전도케이블 기술의 상용화를 위해서 반드시 확보되어야 하며 냉각시스템의 고효율와 함께 장기운전에 따른 냉각시스템의 안정성 및 기기적 특징들이 우선적으로 파악되어야 할 것이다. 본 논문에서는 냉각시스템의 신뢰성을 검증하기 위한 실험의 일환으로 전류와 냉각시스템에 내장되어 있는 히터를 이용하여 열부하를 동시에 인가, 냉각시스템의 냉각용량 과부하 상태를 모의하여 냉각시스템의 반응성을 평가하였다.