• 대한기계학회논문집A
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• 제32권5호
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• pp.402-410
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• 2008

The heavy duty diesel engine must have a large output for maintaining excellent mobility. In this study, a three dimensional finite element model of a heavy-duty diesel engine was developed to conduct the stress analysis. The FE model of the heavy duty diesel engine main parts consisting with four half cylinder was selected. The heavy duty diesel engine parts includes with cylinder block, cylinder head, gasket, liner, bearing cap, bearing and bolts. The loading conditions of engine were pre-fit load, assembly load, and gas load. As the results of structural analysis, because the stress values of cylinder block and bearing cap did not exceed the basic design can be satisfied. But on the part which contacts with cylinder block and bearing cap the stress value exceeds the allowable strength of material. In order to decrease the stress at that part, it was optimized with parametric study.

• Tribology and Lubricants
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• 제21권1호
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• pp.39-45
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• 2005

Investigation of the mass effect on the journal traces in the clearance of engine bearing has been performed for better design of mass distribution of crank system components such as crank pin, piston, con-rod, balance weight, crank throw weight, etc. as well as for better oil reaction behaviors to the applied forces from the cylinder pressures on the bearing. In this preliminary study, crank pin traces in the engine bearing clearance are computed by varying the equivalent magnitude of crank pin mass that includes the masses of crank pin, piston, con-rod. etc.. while most previous studies regarding journal traces in the bearing clearance neglect the inertia effects of crank pin mass. Although the inertia effect of pill mass is negligibly small compared to viscous force by ${\pi}bearing$ theory, it is found that it gives a great amount of influences on the journal traces in full bearing computation $(2\pi\;bearing\;theory)$ under the dynamic loading conditions.

• 대한기계학회논문집B
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• 제22권12호
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• pp.1746-1754
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• 1998

A computer program has been developed to predict the heat transfer characteristics and the temperature distribution in the cylinder block of a 4-cylinder, 4-stroke engine. The finete element method is employed to handle the complex geometries associated with the practical cylinder block. The hexahedron finite element is used for a mesh generation of three-dimensional domain. The present numerical procedure has been validated with the measured temperature at several locations of cylinder block. The heat transfer characteristics of engine cylinder block is systematically analyzed for various engine speeds and loading conditions.

• 한국분무공학회지
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• 제9권4호
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• pp.46-52
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• 2004

An LPG engine (KL6i) for heavy duty vehicle has been developed using liquid phase LPG injection (LPLi) system, which has regarded as one of next generation LPG fuel supply systems. For the KL6i engine, lean burn technology was introduced to minimize the thermal loading and NOx emissions due to an increase of the engine power. In this work, injection timing and piston bowl shape were investigated for the stabilization of lean burn characteristics. Experimental results reveals that fuel stratification induced by these parameters is most effective strategy to extend lean combustion limit in the LPLi system.

• Composites Research
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• 제20권3호
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• pp.63-66
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• 2007

Structural analysis of automotive engine cover under vibration excitation is performed by finite element analysis (FEA) in order to identify the critical area of the structure. Assembly load due to the tightening of the bolts as well as the vibration excitation were considered to describe the actual loading condition. Natural frequencies of the system were extracted considering the damping effect of the structure. Dynamic analysis was performed based on the extracted natural frequency of the system. Experimental modal analysis (EMA) and measurement of strains were performed to verify the results of the analysis. Analysis results correlated closely with the experimental results. Analysis and experiments showed that contribution of the assembly load should not be ignored to predict the structural failure of the engine cover.

• 한국기계연구소 소보
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• 통권17호
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• pp.29-38
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• 1987

A mechanical linkage system to measure the operating temperature of the piston is developed and installed to the engine. Actual temperature distribution is measured for comparison with the numerical results. Heat transfer at the piston is analyzed using an FEM program. Thermal boundary condition of piston surface is determined by analytical and empirical methods. The temperature distribution and the thermal deformation are obtained by the FEM program.

• 오토저널
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• 제10권5호
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• pp.33-41
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• 1988

내연기관에서 crankshaft는 piston에 작용하는 수직 gas force 및 관성력을 회전력으로 바꾸어 주는 역할을 한다. 그러므로 engine작동중 높은 부하를 반복적으로 받기 때문에 이에 견딜 충분한 stiffness를 유지해야 한다. Engine의 stroke 운동시에 gas force와 관성력이 변하고 crankshaft의 형상이 복잡하므로 실제적으로 응력계산은 간단하지 않다. 여기에서는 crankshaft에 작용하는 하중과 반력을 계산하고 crankshaft의 stress 및 safety factor를 계산하여 crankshaft를 설계하는 방법을 설명하고자 한다. 근래 FEM에 의한 stress analysis를 많이 수행하나, loading condition을 주기 위해서는 classical method에 의해서 구할 수 있다.

• 소음진동
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• 제8권1호
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• pp.112-121
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• 1998

In this report, Experimental analysis for main factors and analyzing methods of electro-magnetic noise and no loading noise was conducted because of noise of AC generator, which is peripheral equipment by reduction of engine noise that would be the main cause of vehicle radiation noise. In addition, This is intended to suggest the noise reduction development basis of AC generator for actual fan and electro-magnetic noise by making-analyzing-testing it's sample.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2006년도 춘계 종합학술대회 논문집
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• pp.172-176
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• 2006

게임이 실행될 때 로딩이라는 과정을 거치게 되는데 이 때 텍스처는 게임의 실행 파일 외부에 따로 저장되어 있는 이미지 파일을 불러오게 되는 형태를 취하는 경우가 많다. 이에 이미지 파일의 저장 형식에 따라 로딩 시간이 달라지는 현상이 생기는데 본 연구에서는 다양한 저장형식에 따라 텍스처 파일의 로딩 시간과 저장 용량이 어느 정도 차이가 나는지를 확인해 보고 그 결과를 토대로 텍스처 사용에 대한 최적의 방법을 제시하고자 한다.

• Journal of Advanced Marine Engineering and Technology
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• 제28권5호
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• pp.762-772
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• 2004

Fatigue life of a Piston for large liquid Petroleum liquid injection(LPLi) bus engines is analyzed considering effects of cooling condition parameters : temperature of cooling water, and heat transfer coefficients at oil gallery and bottom surface of piston head. Temperature of the piston is analyzed with varying cooling conditions Stresses of the piston from two load cases of pressure loading. and pressure and thermal loading are analyzed Fatigue life under repeated peak pressure and thermal cycle is analyzed by the strain-life theory. For the two load cases, required loading cycles for engine life are defined, and loading cycles to failure and partial damages are calculated. Based on the resulting accumulated fatigue usage factors, endurance of the piston is evaluated and effects of varying cooling condition Parameters are discussed.