• 항공우주시스템공학회지
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• 제4권1호
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• pp.1-9
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• 2010

As the rocket KSLV-1 called NARO was launched lately, development of domestic rocket technology has been accelerated elastically. Since the rocket technology needs a lot of empirical data, a variety of experiments should be done and lots of time have to be spent for accumulating the foundation of technology. However using a computer can be the solution to close a gap of technique because the simulation can be executed in short time against real experiments and calculate a multiplicity of cases easily. In this research, the transient analysis of turbopump-fed liquid rocket system was worked by the one dimensional modeling. The rocket system consists of the modulized components that are engine, turbopump and so on. For 70 ton class system, the rocket transient process of starting was studied and the performance analysis in steady condition was achieved. In addition, the estimation of nozzle internal flow was investigated by using a nozzle coefficient.

• 유공압시스템학회논문집
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• 제2권1호
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• pp.9-14
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• 2005

Hydraulic excavators have been popular devices in construction field because of its multi-workings and economic efficiency. The mathematical models of excavators have many nonlinearities because of nonlinear opening characteristics and dead zone of main control valve, oil temperature variation, etc. The objective of this paper is to develop a simulator for hydraulic excavator using AMESim. Components and whole circuit are expressed graphically. Parameters and nonlinear characteristics are inputted in text style. The simulator can be used to forecast excavator behavior when new components, new mechanical attachments, hydraulic circuit changes, and new control algorithm are applied. The simulator could be a kind of development platform for various new excavators.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2010년도 제34회 춘계학술대회논문집
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• pp.34-37
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• 2010

터보펌프식 액체 로켓 엔진에 대해 AMESim을 이용하여 1-D 시스템을 구성하고 시동 과도 특성을 해석하였다. 액체산소와 RP-1을 추진제로 사용하는 개방형 사이클에 대해 해석을 수행하였으며, 초기 시동시 가스발생기의 연료 밸브 개방 및 가스발생기 점화 타이밍과 시동 안정성의 관계에 관한 결과를 얻었다. 이러한 연구를 바탕으로 터보펌프식 액체 로켓 엔진 시스템의 최적 설계를 위해 시동시 특성 및 시동 절차를 고려해야 함을 확인 하였다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.864-870
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• 2005

Hydraulic excavators have been popular devices in construction field because of its multi-workings and economic efficiency. The mathematical models of excavators have many nonlinearities because of nonlinear opening characteristics and dead zone of main control valve, oil temperature variation, etc. The objective of this paper is to develop a simulator for hydraulic excavator using AMESim. Components and whole circuit are expressed graphically. Parameters and nonlinear characteristics are inputted in text style. From the simulation results, fixed spring stiffness of MCV can't satisfy accuracy of spool displacement under whole P-Q diagrams. Closed loop type MCV containing proportional gain is proposed in this paper that can reduce displacement error. The ability of closed loop MCV is verified through comparing with normal type MCV using AMESim simulator. The simulator can be used to forecastexcavator behavior when new components, new mechanical attachments, hydraulic circuit changes, and new control algorithm are applied. The simulator could be a kind of development platform for various new excavators.

• 한국자동차공학회논문집
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• 제22권1호
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• pp.52-58
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• 2014

To improve the performance of clutch actuator of clutch-by-wire system for commercial vehicles, it is necessary to understand the driving characteristics of the system. To explain and predict the effects of driving characteristics on clutch characteristics, AMESim software is used. The simulation model of clutch-by-wire system is developed in the AMESim environments under the geometrical dimensions and driving mechanisms of the clutch-by-wire system, such as the rotation speed of the DC motor, the gear ratio of the reducer, the design parameters of the release fork, the coefficient of the clutch diaphragm spring, and so on. The results show that the theoretical analysis of the clutch-by-wire system for commercial vehicles using the AMESim software find out the driving characteristics of the clutch actuator, and predict the performance characteristics of the clutch-by-wire system.

• 한국분무공학회지
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• 제20권1호
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• pp.14-19
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• 2015

Recently, R&D demand for environmental friendly vehicle has rapidly increased due to its global environmental issues such as global warming, energy and economic crisis. Under this situation, the most realistic alternative way for environmental friendly vehicle is a clean diesel vehicle. The common-rail fuel injection system, as key technology of clean diesel vehicle, consists of a high pressure pump, common-rail, high pressure fuel line and electronic control injector. In common-rail high-pressure fuel injection system, high pressure wave of injection system and geometry of injector elements have a major effects on high-pressure fuel spray. Therefore, in this study, the numerical model was developed for analysis about the common-rail fuel pressure pulsation by using AMESim code. We could secure stability of common-rail high-pressure fuel injection system through optimal design of fuel line.

• 한국항공우주학회지
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• 제43권8호
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• pp.722-730
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• 2015

궤도천이용 추력기 시스템에 활용되는 다축 핀틀 추력기 시스템의 구동장치 개수 감소에 대한 필요성으로부터 구동장치 연동 메커니즘을 고안하였다. 본 연구에서는 궤도천이용 추력기 시스템의 주요 임무인 압력제어와 추력분배가 가능한 시스템 설계를 위해 구동장치 개수 감소 가능성 확인 모델을 설계하였다. 가능성 확인 모델을 근거로 피스톤을 적용한 연동 메커니즘을 고안하였고, 수치적 근거와 더불어 AMESim을 활용한 시뮬레이션을 통해 3개의 구동장치로 4개의 핀틀 추력기가 구동 가능하다는 결과를 얻었다.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2010년도 제35회 추계학술대회논문집
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• pp.741-747
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• 2010

발사체의 추진공급시스템에 사용되는 벤트/릴리프밸브는 안전밸브의 조합체로 극저온의 산화제를 주입할 때와 비행 중에 기화된 산소기체를 배출시킨다. 벤트/릴리프밸브의 설계검증을 위해 AMESim과 FLUENT 상용코드를 이용하여 밸브모델을 구성하였다. AMESim 밸브모델을 검증하기 위해 밸브의 개폐압력, 개폐작동시간을 수학적 계산결과와 비교하였고 내부유동해석 결과를 반영하여 모델의 정확도를 높였다. 본 연구에서는 설계인자를 검증 및 작동성능을 분석하였다. 이 결과는 한국형 발사체에 사용되는 다양한 규격의 벤트/릴리프밸브 개발과정의 효율성을 높일 수 있을 것으로 판단된다.

• 드라이브 ㆍ 컨트롤
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• 제16권3호
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• pp.59-66
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• 2019

Hydraulic systems are essential for most of the construction equipments due to their various advantages, such as very powerful, quick response speed, precision control and remote control. Moreover, they are necessary to apply the electro hydraulic systems for precise and remote controls. Operating the small electronic joystick of the remote controller for the control of a multipurpose work machine with remote control technology increases the possibility of a sudden operation compared to the use of a conventional hydraulic joystick. When a joystick is suddenly operated, the peak pressure is generated in the system due to the quick response of the system. Then a vibration is generated due to the peak pressure, which causes instability to the operation of the construction equipment. Therefore, in this study, we confirmed the level of reduction of peak pressure occurring in the electro hydraulic system by using AMESim, when the output signal of the step shape generated by the sudden operation of the electronic joystick was changed by using the convolution operation.

• 드라이브 ㆍ 컨트롤
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• 제16권1호
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• pp.14-21
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• 2019

Axial piston pump is a significant part in wheeled armored vehicle, for generating hydraulic power of vehicle power system. The Axial Piston Pump is a high-performer, core functional item that is developed and applied to most of the military models in the development of military weapon systems. However, in the case of military equipment, there are conditions of limited size and weight required depending on the operating conditions and the operating environment. Under these conditions, it is required that the performance and the environmental resistance are verified to exert the required output. A unique technology is needed for the development of such equipment both in the present and in the future. Therefore, in this study, mathematical modeling of an axial piston pump is presented as a basic data for securing proprietary technology. In addition, a simulation model is designed and compared with the models of six kinds of pistons through simulation. It was established that when the number of pistons of the axial piston pump, which is the development objective, is seven, the model is suitable for the wheeled armored vehicle.