• Journal of the Korean Society of Manufacturing Process Engineers
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• v.8 no.3
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• pp.13-20
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• 2009

Development of a dynamic engine model is essential to predict and analyze of dynamic characteristics from a natural gas engine. Reducing the harmful exhaust emissions can be accomplished by a precise air-fuel ratio control. In this paper, the dynamic engine model was proposed and included mixture formation and intake process because the dynamic characteristics can be affected by the mixture components such as an air and a gaseous fuel. The air mass flow, the partial pressure ratio, and the gas constant are changed by variations of the components in the mixture formation and intake process. The dynamic engine model is applied to the natural gas engine for validation test. Experimental results show that the dynamic engine model is effective to predict the dynamic characteristics of the natural gas engine.

• Journal of the Korean Society of Propulsion Engineers
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• v.22 no.6
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• pp.126-133
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• 2018

A liquid rocket engine experiences various static loads in flight, such as high pressures due to propellents, thrust and thermal loads due to cryogenic liquid oxygen and combustion gas with extreme vibration. During the engine development stage, structural analyses and investigation on the strain measured from ground firing tests are necessary for determining the structural reliability of the engine. In this study, the strain characteristics, obtained from the ground firing tests of a 75 tonf-class engine, were analyzed.

• 한국기계연구소 소보
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• s.9
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• pp.7-20
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• 1982

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2002.10a
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• pp.25-38
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• 2002

• International Journal of Automotive Technology
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• v.7 no.5
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• pp.519-526
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• 2006

For investigating the effect of fuel stratification on flame propagation, initial flame development and propagation were visualized under different axially stratified states in a port injection SI engine. Stratification was controlled by the combination of the port swirl ratio and injection timing. Experiments were performed in an optical single cylinder engine modified from a production engine and images were captured through the quartz window mounted in the piston by an intensified CCD camera. Firstly in this paper, the characteristics under no port-generated swirl condition, i.e. normal conventional case was studied. Under various stratified conditions, flame images were captured at the pre-set crank angles. These were averaged and processed to characterize the flames propagation. The flame stability was estimated by the weighted average of flame area and luminosity. The stability was also evaluated through the standard deviation of flame area and propagation distance, and mean absolute deviation of propagating direction. Results show that stratification state according to injection timing do not affect on the direction of flame propagation. The flame development and the initial flame stability are strongly dependent on the stratified conditions and the initial flame stability is closely related to the engine stability and lean misfire limit.

• Journal of Advanced Navigation Technology
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• v.14 no.5
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• pp.718-724
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• 2010

The Unreal Engine is a free game engine developed by Epic Games. In this paper, we propose a First Person Shooter (FPS) game development using free Unreal Development Kit. The merit of Unreal engine provide a hight degree of portability, and it is a tool used by many game developers today, supporting a multitude of platforms on personal computers and many video game consoles with free toolkit. But it is required high-performance PC to develop game. This toolkit doe s not high-quality computer programming skill, just possible to develop FPS game easily.

• International Journal of Automotive Technology
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• v.8 no.2
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• pp.243-248
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• 2007

The durability of a cylinder head is influenced by the thermal and mechanical history during the manufacturing process, as well as engine operation. In order to improve the durability of cylinder head, both load from engine operation and the preload conditions from the manufacturing process must be considered. The aluminum cylinder head used for a HSDI diesel engine is investigated to reduce the possibility of high cycle fatigue crack in this study. FE analysis is performed to elucidate the mechanism of high cycle fatigue crack in the HSDI diesel cylinder head. Two separate approaches to increase the durability of the cylinder head are discussed: reducing load from engine operation and re-arranging preload conditions from the manufacturing process at the critical location of the cylinder head. Local design changes of the cylinder head and modification of pretension load in the cylinder head bolt were investigated using FE analysis to relieve load at the critical location during engine operation. Residual stress formed at the critical location during the manufacturing process is measured and heat treatment parameters are changed to re-arrange the distribution of residual stress. Results of FE analysis and experiments showed that thorough consideration of the manufacturing process is necessary to enhance the durability of the cylinder head.

• 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.

• The Journal of the Korea Contents Association
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• v.5 no.3
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• pp.133-140
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• 2005

It is important matter to develop game that language should consider improving game development environment. It is hardly any language that is designed to develop a game. Most developer used general purpose programming language in these situations, and directly modeling with engine. For this reasons, developers cannot easily develop games and must programming on engine level. It is hard to develop a game in this environment that was not able to understand an engine well. Moreover, developer and planner want to use an abstracted high-level language on planner phase and are going to easily develop a game. It was not have communication tool between developer and planner. Therefore, we defined a script language for modeling based on abstract engine level. In addition, we did build IDE to develop game using abstracted high-level language. It was able to develop a game on high-speed development environment. Therefore, developer does not must develop with engine phase but can develop a game with planners. In addition, game planner and developer can use a communication tool because it is able to develop skeleton game.

• Journal of Aerospace System Engineering
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• v.14 no.3
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• pp.60-68
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• 2020

If a broken blade in the aircraft engine penetrates the casing and ejects outside the aircraft, it will impact the fuselage, threatening the safety of the passengers. Thus, the development of a engine case should be certified for stability evaluation by the Aviation Administration. In this paper, we investigated the requirements and development technology for the containment certification of the engine casing necessary for the independent engine development in the country. An experimental/analytical method has been identified to summarize the contact safety requirements presented by the U.S. and European aviation agencies to verify the containment of debris in the casing corresponding to this certification. Also, we analyzed recent research on the containment casing and verification methods in casing development.