• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2008년도 제30회 춘계학술대회논문집
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• pp.103-106
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• 2008

본 연구에서는 발사체 비행 중 가속도의 변화로 발생하는 엔진 입구압력의 변화를 고려하여 엔진의 구성품에 미치는 영향을 고찰하였고 그에 따른 엔진 성능 변화를 예측하였다. 엔진의 입구압은 탱크 내의 추진제 수두와 가압 압력 및 압력 손실 등으로 정의되며 이에 따라 발사체가 비행하면서 추진제 소모와 가속도 변화에 의해 입구압력이 변하게 된다. 입구압이 변할 때 펌프 토출압이 변하고 그에 따른 유량 변화로 가스발생기의 압렵변화가 발생하며, 이는 터빈의 출력변화로 이어져 다시 펌프의 토출압 변화로 나타남을 알 수 있었고, 이는 궁극적으로 주연소실의 연소압 변화를 이끌면서 엔진의 성능이 변화함을 알 수 있었다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1987년도 한국자동제어학술회의논문집; 한국과학기술대학, 충남; 16-17 Oct. 1987
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• pp.541-546
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• 1987

An experimental study has been conducted to investigate the suction performance of a designed inlet. Total pressure distortion in the inlet S-duct was measured and the effect of lip thickness and throat area was analyzed. The volume flow rate of air into the turbojet engine was controlled to observe the effect of engine RPM to the total pressure distortion. The pressure data from 36 air tubes were obtained using scanivalve, pressure transducer, and visicoder system.

• 한국자동차공학회논문집
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• 제10권5호
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• pp.35-44
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• 2002

Engine cycle simulation using a two-zone model was performed to investigate the effect of the engine parameters on NO and soot emissions in a DI diesel engine. The present model was validated against measurements in terms of cylinder pressure, BMEP, NO emission data with a 2902cc turbocharger/intercooler DI diesel engine. Calculations were made for a wide range of the engine parameters, such as injection timing, ignition delay, Intake air pressure, inlet air temperature, compression ratio, EGR. This parametric study indicated that NO and soot emissions were effectively decreased by increasing intake air pressure, decreasing inlet air temperature and increasing compression ratio. By retarding injection timing, increasing ignition delay and applying EGR. NO emission was effectively reduced, but the soot emission was increased.

• 한국분무공학회지
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• 제14권1호
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• pp.34-38
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• 2009

This paper presents the pulsation of carburetor inlet and outlet pressure of a small SI gasoline engine. The engine used in this paper is a 23cc, single cylinder, diaphragm carburetor, two-stroke, air-cooled for brush cutter. The rpm and pressure wave pulsation at the inlet and the outlet of carburetor were measured and analysed for the understand of the internal air flow into the barrel on the diaphragm carburetor. These data should be used for the development of the duel fuel injection system for gasoline and LPG. The results showed that the carburetor inlet pressure variations were very steady, but the pressure variations at carburetor outlet were very sensitive to the pressure variation into the crank case and were to similar independently to the engine speed on partial opened throttle conditions. According to increasing engine speed, the pressure waves started to come out and be developed after closing the intake port of the engine at carburetor outlet. Reverse flow occurred on the WOT (wide open throttle) condition.

• 융복합기술연구소 논문집
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• 제4권2호
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• pp.61-65
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• 2014

Pressure distribution around rotating impeller blades in centrifugal pump has been main issue for design of efficient and high performance automotive water pump. In addition, pressure losses of inlet water pipes should be considered to reduce additional pressure drop and design high performance engine cooling system. In this paper, pressure distribution inside water pump and pressure drop between inlet and outlet of water pump are investigated numerically to design plastic water pump for clean diesel engine application. And the inlet geometry of water pump was considered to analysis the effect of inlet water pipe geometry on pressure distribution around impeller blades and outlet pressure. The prediction results are compared with experimental data to validate and determine optimal operation condition without water pump cavitation. Major design parameters such as blade angle, volute geometry, system pressure, and coolant flow rate are considered to confirm applying possibility of plastic blades to the clean diesel engine.

• 오토저널
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• 제13권6호
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• pp.48-56
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• 1991

This paper describes the experimental investigations on the pressure variations of intake and exhaust manifold and mass flow rate through exhaust turbine of turbocharged 6-cylinder diesel engine. The turbocharger of experimental diesel engine is constructed with the radial ty pe exhaust turbine and blower driven by exhaust gases. The pressure variations were measur ed by pressure transducer at the points such as turbine inlet and outlet, compressor inlet and outlet, and inlet pipe and exhaust manifolds for normal and combined charging engines with the change of engine speed. The experimental results of this study show that the mass flow rate of exhaust turbine and the variations of pressure in intake and exhaust manifold are all increased with the increase of engine speed.

• 항공우주기술
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• 제6권2호
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• pp.29-34
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• 2007

본 논문에서는 엔진고공환경 시험설비의 엔진 입구 덕트에서 측정한 전압력과 전온도를를 통해 실시간으로 공기유량을 계산하고, 압력프로파일을 이용하여 경계층 레이크를 장착하지 않았을 경우에도 공기유량을 예측할 수 있는 방법을 기술하였다. 또한, 엔진입구배관에 걸친 덕트 연결부를 통한 압력손실을 예측하고, 이를 통해 공기유량을 보정함으로써, 고공환경시험설비에서의 공기유량측정의 신뢰도를 향상시키고 설비유지측면에서 운용성을 보고자 하였다.

• 한국유체기계학회 논문집
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• 제15권5호
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• pp.27-31
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• 2012

Turbine inlet temperature is steadily increasing to achieve high specific thrust and efficiency of gas turbine engines. Turbine cooling technology is essential to increase turbine inlet temperature. For this study, a small or medium sized aircraft engine of 10,000 lbf class with the turbine inlet temperature of $1,400^{\circ}C$, the engine overall pressure ratio of 32.2, and the bypass ratio of 5 was set as the baseline model and its performance analysis was performed at the design point. The engine has the performance of 10,013 lbf thrust and the specific fuel consumption of 0.362 lbm/hr/lbf. The thrust and the specific fuel consumption of the baseline model were compared with those of similar class engines. Based on these results, the turbine design requirements were assigned. In addition, the parametric analysis of the engine, related to aerodynamic and cooling design of the high pressure turbine, was performed. Based on the baseline model engine, the influence of turbine inlet temperature, cooling flow ratio, and high pressure turbine efficiency variations on the engine performance was analyzed.

• 항공우주시스템공학회지
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• 제1권1호
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• pp.53-59
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• 2007

Inlet distortion test was performed at Korea Aerospace Research Institute in order to evaluate the degradation of engine performance under the distorted inlet condition. In this paper, only the inlet pressure distortion was taken into consideration. During the development process of the inlet distortion test technique, variable distortion screen was designed and evaluated under various test conditions to establish the experimental database of distortion for engine test. The result of inlet distortion test for engine shows that the operating point was changed toward the worse direction and the degradation of engine performance by inlet distortion was verified.

• International Journal of Aeronautical and Space Sciences
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• 제8권2호
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• pp.121-125
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• 2007

In late 1960's, engineers of the engine manufacturer experienced that the distortion of inlet flow of turbofan and turbojet engine could cause the surge in compressor and affect overall engine operational performance, which result in the deterioration of stability of the engine. In this study, block type of inlet distortion simulating device has been developed in order to investigate the effect of inlet distortion on the deterioration of overall engine operational performance. The inlet distortion simulating device was installed in front of engine inlet in order to simulate distortion of inlet flow. The degree of inlet distortion was measured by rakes installed upstream the inlet distortion simulating device and between the engine inlet and inlet distortion simulating device. Before applying the inlet distortion simulating device to real engine, preliminary tests were performed with a simulated engine in order to verify the degree of inlet distortion by the device. Preliminary inlet distortion tests were performed in Altitude Engine Test Facility(AETF) of Korea Aerospace Research Institute(KARI) and results showed that the inlet distortion simulating device could be used in simulating various inlet distortion cases.