• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.7
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• pp.105-111
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• 2006

The aircraft engine is to generate thrust for the maneuver of aircraft and to provide the power to the related hydraulic system and electrical system. Since the power provided to the systems is extracted from the high pressure compressor of aircraft engine, the extracted power is called horsepower extraction (HPX). If the HPX provided from the engine is smaller than the HPX required from the related systems, there could be abnormal engine behavior, like engine rollback or stall. Analysis on comparing the required HPX and the engine HPX capability had been performed during the T/A-50 FSD (Full Scale Development) period. The analysis results make the engine schedule changed, and T/A-50 flight test has been performed with the changed engine schedule. The analysis results and changing the engine control schedule were verified to be valid with the flight test results.

• Proceedings of KOSOMES biannual meeting
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• 2006.05a
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• pp.213-216
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• 2006

In this paper a development of shaft power measuring system for a small vessel is discussed. It is important that the exact power measurement of marine engine which is used for ship's propulsion since the engine power is related to ship's usage and its shaft design. Two gearwheel and magnetic sensors are adopted to measure torsional angle on the shaft. High resolution encoder is also applied to compensate the output signal from gearwheel. The calculation of shaft power is executed using measured signal and angular velocity of rotating machine and the result is plotted on the monitoring screen.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2003.10a
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• pp.253-256
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• 2003

The engine core of a 65hp-turboshaft engine for UAV is developed and modified into a 55lbf-turbojet engine. Since the core engine is installed with a propelling nozzle, which has the same mass flow characteristics as the power generator of the turboshaft engine its mechanical and aerodynamic characteristics are basically the same as those of the complete engine. Engine output is not shaft power but thrust force that is easier to measure. The core engine is very useful for core test purpose. Besides, the core engine itself can be directly used for propulsion of small air vehicles.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2001.04a
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• pp.63-67
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• 2001

초등훈련기 KT-1의 주 추진기관인 터보프롭엔진(PT6A-62)의 정상상태성능해석 프로그램을 개발 하였다. 비행 마하수 0의 조건에서 장착손실을 고려하여 정상상태 성능해석을 수행하였다. 해석결과는 엔진 제작사에서 제시한 성능 및 상용 정상상태 성능해석 프로그램인 GASTURB와 비교하였다. 해석결과 공기유량, 축마력은 고도상승시 감소함을 나타내었고 비 연료 소모율은 미소한 상승을 확인할 수 있었다. 장착조건과 비 장착 조건의 비교 결과 엔진 전체 손실이 증가할수록 축 마력은 감소하고 비 연료 소모율은 증가함을 확인할 수 있었다.

• Bulletin of the Society of Naval Architects of Korea
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• v.31 no.4
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• pp.10-13
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• 1994

최근 선박의 대형화, 고속화로 인하여 추진기의 부하가 증가되고 있으며, 특히 최근 등장한 1,000TEU급 콘테이너선의 경우 추진기가 흡수해야되는 축마력이 70,000HP 이상인 경우도 잇다. 커다란 축마력을 흡수하여 선박을 빠른 속도로 추진시켜야 되는 최근의 추진기는 작동 원리상 캐비테이션 발생을 피할 수 없으며 캐비테이션 발생량의 허용범위 및 캐비테이션 거동의 특성을 고려하여 추진기를 설계하여야 된다. 캐비테이션의 여유가 없이 추진기 설계가 수행되기 때문에 추진기 캐비테이션의 성능해석은 엄밀한 정밀도가 요구된다. 캐비테이션이란 일정한 온도에서 유체동력학 작용에 의해서 유체주위의 압력이 일정한 압력(예 : 증기압) 이하로 낮아질 때 물이 기화하여 수증기로 변하면서 빈 공간을 형성하는 현상을 말한다. 이렇게 발생된 캐비티는 주위 압력환경에 따라 생성, 성장, 수축, 붕괴의 과정을 거치게 된다. 특히 붕괴의 과정은 짧은 시간 내에 급격히 진행되기 때문에 진동 및 소음의 원인이 되고, 심할 경우 추진기 혹은 주위 물체 표면에 침식작용의 원인이 되기도 한다. 본 고에서는 캐비테이션의 물리적 특성 및 분류방법을 간단히 소개하고, 캐비테이션에 의한 선박추진기의 성능저하 특성 및 모형시험 기법을 이용한 캐비테이션 성능해석법을 소개하였다.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2007.04a
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• pp.448-452
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• 2007

본 논문은 선박의 축계마력 측정방법 및 측정시스템의 개발방법에 대해 논의한다. 엔진 축계에서의 정확한 출력은 선박의 사용목적, 관련추진축계의 제작 및 설치비용 등과 밀접한 관련을 맺고 있다. 본 연구에서는 동력 전달측과 부하측사이의 축상에 두 개의 기어휠을 설치하고 각각의 기어휠에 비접촉식 검출기를 부착하여 위상을 계측한다. 동력이 가해질 경우 두 지점에서는 비틀림 각에 의한 위상차가 발생하게 되고, 발생된 위상차를 전압신호로 검출하여 축에서의 마력을 계산하게 된다.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2001.04a
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• pp.76-79
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• 2001

SIMULINK^{$\circledR}$를 이용하여 항공기용 터보프롭 엔진을 모델링한 후 현재 KT-1의 추진기관인 PT6A-62 분리축 터보프롭엔진의 성능을 해석하였다. SIMULINK^{$\circledR}$ 모델의 검증을 위하여 상용해석프로그램인 GASTURB 와 비교한 결과 최대오차율 1.07% 이내로 확인되었다. 지상정지 조건에서 블리드 공기유량을 0에서 5%, 보기류 구동에 따른 출력손실을 0에서 20 hp로 가정하고 해석한 결과 축마력은 최대 0.68%감소하며 비연료소모율은 거의 영향을 받지 않음을 알 수 있었다.

• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.7
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• pp.1780-1786
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• 1995

The main goal of the present study is to establish the techniques and methodolgies of turbine performance test through evaluating the objective turbine test piece, and checking the reliability of the self-developed test facility by performing a series of turbine tests under ambient temperature condition. A high speed coupling, a lubrication system and a test bed of the test facility were modified through a series of preliminary test in order to reduce the vibration and oil leakage. The flowrate control of the test facility and data acquisition were accomplished by using a software called "Labview" The measurement of shaft horse power and control of rotational speed according to the conditions of turbine rotation were performed by a separate system. The preliminary evaluation of the measured data suggests that the developed test facility and the test technique can be used reliably for the performance test of turbines with the minor improvement.provement.

• Journal of the Korean Society of Propulsion Engineers
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• v.8 no.3
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• pp.17-26
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• 2004

In this paper, power transmission systems converts the shaft power of a Turbo-shaft Engine with Free Power Turbine into the generator power and be composed of a method being supplied in the thrust motor driving a propellers. Being used this, Gas turbine engine works to flat rating about 110 kw (147 shp) that the thrust motor be extremely supplied from the engine of 317shp. In this test equipment, the engine is installed with the flywheel being able to the damping function when happen to the varying load between gas turbine engine output-shaft and generator. Then if the flywheel of inertial moment be not considered, the generator and motor not get the required power from the engine for raising the load. Also it is certified that the engine works the abnormal operation. Hence the flywheel of inertial moment is determined the required range to do the performance analysis with the dynamic transient from the given and tested engine data. This system is able to get the required power after a mounting test with the redesigned flywheel.

• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.4
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• pp.429-435
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• 2020

Different methods are used for determining the output of engines to obtain the indicated horsepower by measuring the combustion pressure of cylinders, and to obtain the shaft horsepower by measuring the shaft torque. It is difficult to examine the shaft torque using the condition of the cylinder, and the most accurate method used for determining the combustion pressure involves examining the combustion state of the cylinder to evaluate the engine performance and analyze the combustion of the cylinder. During the measurement, the combustion pressure is the most important parameter used for accurately determining the cylinder angle because the cylinder pressure is indicated based on the angle of the crankshaft. In this study, an encoder was used as the crank angle sensor to measure the cylinder pressure on the generator engine of the actual operating ship. The reasons for the differences between the top dead center (TDC) recognized by the encoder (TDC_encoder) and the TDC recognized by the compression pressure (TDC_comp) were considered. The dif erences between the TDC_comp and TDC_encoder of the cylinders measured at idle running, 25 %, 50 %, and 60 % loads were analyzed to determine for the crankshaft production effect, the crankshaft torsion effect owing to the increased rotational resistance from the increased load, and the coupling damping effect between the engine and generator. It was confirmed that the TDC error occurred up to 3° crank angle as the load of the generator increased.