• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2002.04a
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• pp.24-24
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• 2002

가스터빈 엔진의 공력 성능은 작동 유체인 공기의 물성 변화에 대하여 민감하게 반응하는데, 대기 중에 수증기 형태로 함유되어 있는 수분이 공기의 물성 변화를 야기하는 대표적인 요인이다. 건공기와는 다른 화학적 조성을 가지는 습한 공기가 가스터빈 엔진에 유입되면 엔진의 작동과 성능에 2가지 방법(공기 흡입 도관에서의 응축 그리고 엔진 전체 사이클에 걸친 가스 조성 변화 야기)으로 영향을 미친다. 절대 습도가 높은 지상 조건의 무더운 날에는 습공기 유입으로 인한 가스터빈 엔진의 성능 저하가 두드러지며 지상에서의 고공환경시험에서는 시험 당일의 습도 조건에 따라 성능의 차이를 보인다. 해상에서 운용되는 비행체 추진기관으로 사용되는 가스터빈의 경우 특히 높은 습도 환경에서 작동하므로 습도 보정을 통하여 엔진의 정확한 성능과 운용성을 파악하는 것은 중요하다.

• Journal of the Korean Society of Propulsion Engineers
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• v.19 no.2
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• pp.65-72
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• 2015

Performance tests of a turbopump for the developing 7-tonf liquid rocket engine were conducted. The performance of turbopump components and their power matching were measured and examined firstly under the LN2 and water environment. In the real propellant(LOX and kerosene) environment tests, design and off-design performances of turbopump were fully verified. During the off-design tests, turbopump running time was set the same as engine operating time and pump inlet pressure were set lower than nominal operating value in order to investigate pump suction capability. It have been verified that subject turbopump satisfies required performance - flow rate, head, suction performance and operational time - in the operating regime of developing liquid rocket engine.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2002.07a
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• pp.241-246
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• 2002

본 연구는 농산물을 건조할 때 배풍구로 버려지는 열을 회수하여 건조열원으로 재이용할 수 있는 배풍열 회수장치를 개발하여 연료절감 및 열회수장치의 성능을 분석한 연구 결과 다음과 같은 결론을 얻었다. 가. 농산물건조기의 열수지를 분석한 결과 투입열량을 100%로 하였을 경우, 배기열은 13.2%, 배풍역량 77.7%, 관류열량은 9.1%로 나타났다. 나. 고추를 건조시 배풍구입구온도가 55-6$0^{\circ}C$일 때 배풍구 출구온도 41-43$^{\circ}C$, 일때 흡입구 입구온도는 25-28$^{\circ}C$, 흡입구 출구온도는 41-43$^{\circ}C$로 나타나 건조실로 41-43$^{\circ}C$의 높은 온도를 투입할 수 있었다. 다. 배풍열 량이 단위 시간당 4700kca1에서 6000kca1로 증가할 때, 흡입 열량은 2200kca1에서 3000kca1로 나타났다. 라. 고추의 초기함수율이 80%에서 15%까지 떨어지는데 관행건조는 약 27시간이 경과했으며, 배풍연회수건조를 할 경우는 약 24시간이 경과했으며 그 결과 배풍열 회수건조가 약 3시간정도 소요시간이 단축되었음을 알 수 있었음. 마. 배풍열 회수장치를 사용하여 농산물건조기 투입량의 47%, 배풍열량의 64%의 열량을 회수할 수 있었다. 바. 배풍열 회수 농산물건조기 성능시험 결과 고추 100kg 건조시 연료소모량은 43%, 건조 소요비용은 21% 감소시킬 수 있었다.

• Fire Science and Engineering
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• v.29 no.2
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• pp.84-91
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• 2015

The purpose of this study is to suggest the reasonable model of the caliber in suction nozzle, the pressure of suction nozzle, and the flow rate about foam system of line proportioner type using in the pumpcar. To test this, the experimental study was accomplished on the ground of the standards for the Performance Certification and Product Inspection of Foam Fire-extinguishing Chemical Mixing Machine. Aqueous Film Forming Foam in 3% and pipe type air foam nozzle with line proportioner FE 40 type were used. Test result showed that the pressure of suction nozzle within the limits between 0.25 MPa and 0.35 MPa was appropriate when the caliber in suction nozzle is 4 mm. Also, the pressure of suction nozzle within the limits between 0.45 MPa and 0.60 MPa was appropriate in the higher pressure than 4 mm when the caliber in suction nozzle is 5 mm.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2004.10a
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• pp.47-52
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• 2004

In the design of scramjet intake for hypersonic flight, a variety of aerothermodynamics phenomena are encountered. These phenomena include blunt leading - edge effects, boundary layer development issues, transition, inviscid / viscous coupling, shock - shock interactions, shock / boundary - layer interactions, and flow profile effects. For intakes that are designed to operate within a narrow Mach number / altitude envelope, an understanding of a few of these phenomena might be required. In this work several predominant flowfield phenomena (viscous phenomena, boundary - layer separation, and combustor entrance profile) are discussed to investigate the performance of the intake at the altitude and angle of attack extremes of the HyShot flight experiment.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.41 no.4
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• pp.253-260
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• 2013

Ice accretions on the surface around a rotorcraft air intake can deteriorate the safety of rotorcraft due to the engine performance degradation. The computational simulation based on modern CFD methods can be considered extremely valuable in analyzing icing effects before exact but very expensive icing wind tunnel or in-flight tests are conducted. In this study the range and amount of ice on the surface of anti-icing equipment are investigated for heat-on and heat-off modes. It is demonstrated through the computational prediction and the icing wind tunnel test that the maximum mass and height of ice of heat-on mode are reduced about 80% in comparison with those of heat-off mode.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.8
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• pp.5082-5088
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• 2015

In this paper, durability test of 1000cc level gasoline engine has been carried out. Durability test set total 300 hours and WOT condition. Engine torque, power, fuel consumption, blow-by gas flow rate, and oil pressure are measured to analyse performance variation by time. As a result, engine performance of high rpm range gradually reduced by time but for relatively low rpm range shows stable performance. Blow-by gas flow rate shows 0.4% of averaged induction air flow rate, which is excellent rate for 1000cc level gasoline engine. Engine torque and fuel consumption data show the break-in upto 100 hours and aging trend after that. After 300 hours, engine is disassembled and each part is checked for the damage or crack.

• Journal of the Korean Society of Propulsion Engineers
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• v.22 no.3
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• pp.97-108
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• 2018

It is definitely important to measure thrust during ground test when developing air-breathing engine, and in case of air-breathing engine, gross thrust should be calculated considering not only the measured thrust but also the force induced by the air flow of engine intake. Also, side thrust like yaw and pitch should be measured and analyzed using multi-component thrust measurement system. Engine performance was accurately evaluated by calculating the gross thrust of air breathing engine precisely which is analyzed from below serial procedure: labyrinth seal isolation, 1-axis gross thrust calculation, develop multi-component thrust measurement system, and side thrust analysis.

• Aerospace Engineering and Technology
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• v.5 no.2
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• pp.37-46
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• 2006

The outside environment is very severe while aircraft is cruising. Especially small particle of icing in cold air condition can have negative influence on aircraft performance. If ice particle is attached to leading edge of wing, it can change wing configuration and decrease flight quality. If icing particle is attached to inlet of engine, it can damage compressor blade and have negative influence to aircraft safety. We make icing simulation device with liquid air system for analyzing about variation of engine performance due to incoming of icing to engine.

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.1
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• pp.85-91
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• 2021

Aggregate waste separator with rotating separating net was designed for applying classification process of construction waste. In order to evaluate the performance of the aggregate waste separator, according to the type of waste, standardized waste samples are prepared using acrylic. The appropriate operating point was evaluated by the classification efficiency and misclassification rate of recycled aggregate according to the control frequency of the blower operating and inlet position of the separating net. The classification efficiency at the operating point of the aggregate waste separator was evaluated through flow analysis assuming recycled aggregate and waste sample as particles. As a result of the performance test, when the distance. between the conveyor belt and the inlet was 0.2m, the classification efficiency was 95%, but the misclassification rate of recycled aggregate was 2% or more, which satisfies the classification efficiency and the misclassification rate of less than 2%. The operating point was shown at a control frequency of 58Hz at a suction distance of 0.254m. As a resu lt of flow analysis, there was no misclassification of recycled aggregate. In order to redu ce constru ction waste in the existing recycled aggregate production process, adsorption system using a rotating separating net that can be operated as an installation type was built.