• Title/Summary/Keyword: Automotive cylinder head

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Response of a prototype brain material subjected to rotational acceleration (회전가속에 대한 프로토타입 뇌재료의 반응)

  • Lee, E. S.
    • Journal of the korean Society of Automotive Engineers
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    • v.11 no.5
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    • pp.76-89
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    • 1989
  • With the objective of studying the response of brain tissue in a transient rotational acceleration of the head, as occurs in car crash, the problem of a cylindrical case containing a prototype brain material of silicone gel and subjected to a rotational acceleration around the axis of the cylinder is analysed. The prototype material is considered to be homogeneous and isotropic, and is modeled alternatively as a linear elastic or a linear viscoelastic solid. The computational model for the present problem consists of a 3-dimensional isoparametric finite element model, wherein large deformations and large strains are treated through the updated Lagrangian approach. A comparison of the results of the present 3-dimensional computations, with the attendant assumptions on material data, is made with the results of independent experimental study. The deformation profiles and the major characteristics of response of the brain material are in good agreement with the test results. Moreover, the study suggests the possibility that the use of more accurate material data may yield very useful results even appropriate for accurate quantification of deformations.

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On the flame propagation in a spark-ignited gasoline engine (전기점화식 내연기관에 있어서 화염전파에 관한 연구)

  • 이종원;이형인
    • Journal of the korean Society of Automotive Engineers
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    • v.4 no.2
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    • pp.69-78
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    • 1982
  • The purpose of this study is to investigate the flame propagation phenomenon in the combustion chamber of spark-ignition gasoline engine for the idling condition. by means of four ion probes located through the cylinder head, the time intervals for the flame to arrive at the respective probes are read on th visicorder char. As results, the flame is considered to initiate after some ignition delay and to propagate through the central space of combustion chamber with rather constant speed on the order of 25m/sec, and thereafter to be slowed down approaching the wall. Additionally, the retardation of flame in the wall boundary layer could be inferred. The maximum pressure is developed when the flame nearly touches the wall diagonal to the spark plug. And some features of flame propagation are elucidate.

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A Study on the Kernel Formation & Development for Lean Burn and EGR Engine (희박연소 및 EGR 엔진에서 초기 화염액 생성 및 성장에 관한 연구)

  • 송정훈;선우명호
    • Transactions of the Korean Society of Automotive Engineers
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    • v.7 no.8
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    • pp.24-33
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    • 1999
  • This paper investigate the effects of the variations of engine operation condition in the flame kernel formation and developmnet . A model for calculating the initial kernel development in spark ignition engines is formualted. It considered input of electrical energy, combustion energy release and heat transfer to the spark plyg, cylinder head, and unburned mixture. The model also takes into accounts strain rate of initial kernel and residual gas fraction. The breakdown process and the subsequent electrical power input initially control the kernel growth while intermediate growth is mainly dominated by diffusion or conduction. Then, the flame propagates by the chemical energy and turbulent flame expansion. Flame kernel development also influenced by engine operating conditions, for example, EGR rate, air-fuel ration and intake manifold pressure.

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A Case Study of Simulation for the Design of Crankshaft Line in an Automotive Engine Shop (자동차 엔진공장의 크랭크샤프트 라인설계를 위한 시뮬레이션 사례연구)

  • Moon, Dug-Hee;Xu, Te;Shin, Woo-Young
    • Journal of the Korea Society for Simulation
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    • v.17 no.2
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    • pp.1-12
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    • 2008
  • The major components of an engine are the cylinder block, cylinder head, crankshaft, connecting rod, and camshaft, which are more popularly known as the 5 C's. Thus, the engine shop usually consists of six sub-lines, including five machining lines and one assembly line. The flow line is the typical concept of the layout when the engineer designs the engine shop. This paper introduces a simulation study regarding the new crankshaft machining line in a Korean automotive factory. The major factors for designing the machining line are considered, and their effects on the system performance are evaluated with a three-dimensional(3D) simulation model that is developed with $QUEST^{(R)}$. The initial layout is analyzed using the simulation model, and we suggest some ideas for improvement.

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High Temperature Fatigue Deformation Behavior of Automotive Heat Resistant Aluminum Alloys (자동차 부품용 내열 알루미늄 합금의 고온 피로 변형 거동)

  • Park, Jong-Soo;Sung, Si-Young;Han, Bum-Suck;Jung, Chang-Yeol;Lee, Kee-Ahn
    • Korean Journal of Metals and Materials
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    • v.48 no.1
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    • pp.28-38
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    • 2010
  • High temperature high cycle and low cycle fatigue deformation behavior of automotive heat resistant aluminum alloys (A356 and A319 based) were investigated in this study. The microstructures of both alloys were composed of primary Al-Si dendrite and eutectic Si phase. However, the size and distribution for eutectic Si phase varied: a coarse and inhomogeneous distributed was observed in alloy B (A319 based). A brittle intermethallic phase of ${\alpha}-Fe\;Al_{12}(Fe,Mn)_3Si_2$ was detected only in B alloy. Alloy B exhibited high fatigue life only under a high stress amplitued condition in the high cycle fatigue results, whereas alloy A showed high fatigue life when stress was lowered. With regard to the low-cycle fatigue result ($250^{\circ}C$) showing higher fatigue life as ductility increased, alloy A demonstrated higher fatigue life under all of the strain amplitude conditions. Fractographic observations showed that large porosities and pores near the outside surface could be the main factor in the formation of fatigue cracks. In alloy B. micro-cracks were formed in both the brittle intermetallic and coarse Si phasese. These micro-cracks then coalesced together and provided a path for fatigue crack propagation. From the observation of the differences in microstructure and fractography of these two automotive alloys, the authors attempt to explain the high-temperature fatigue deformation behavior of heat resistant aluminum alloys.

An Experimental Analysis for System Optimization to Reduce Smoke at WOT with Low Volatile Fuel on Turbo GDI Engine (저 기화성 연료를 사용한 직접분사식 과급 가솔린엔진에서 전 부하 스모크 저감을 위한 시스템 최적화에 관한 연구)

  • Kim, Dowan;Lee, Sunghwan;Lim, Jongsuk;Lee, Seangwock
    • Transactions of the Korean Society of Automotive Engineers
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    • v.23 no.1
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    • pp.97-104
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    • 2015
  • This study is a part of the high pressure injection system development on the Turbo GDI engine in order to reduce smoke emission in case of using the low volatile(high DI) fuel which is used as normal gasoline fuel in the US market. Firstly, theoretical approach was done regarding gasoline fuel property, performance, definition of particle matters and its creation as well as problems of the high DI fuel. In this experimental study, 2L Turbo GDI engine was selected and optimized system parameter was inspected by changing fuel, fuel injection mode (single/multiple), fuel pressure, distance between injector tip and combustion chamber, start of injection, intake valve timing in engine dyno at all engine speed range with full load. In case of normal gasoline fuel, opacity was contained within 2% in all conditions. On the other hands, in case of low volatile fuel (high DI fuel), it was confirmed that the opacity was rapidly increased above 5,000 rpm at 14.5 ~ 20 MPa of fuel pressure and there were almost no differences on the opacity(smoke) between 17 MPa and 20 MPa fuel pressure. According to the SOI retard, smoke decrease tendency was observed but intake valve close timing change has almost no impact on the smoke level in this area. Consequently, smoke decrease was observed and 16% at 6000rpm respectively with injector washer ring installed. By removing injector washer to make injector tip closer to the combustion chamber, smoke decrease was observed by 46% at 5,500 rpm, 42% at 6,000 rpm. It is assumed that the fuel injection interaction with cylinder head, piston head, intake and exhaust valve is reduced so that impingement is reduced in local area.

Development of Conversion Technology of a Decrepit Diesel Vehicle to the Dedicated Natural Gas Vehicle (노후 디젤차량으로부터 전소 천연가스자동차로의 개조 기술 개발)

  • Ryu, Kyung-Hyun;Kim, Bong-Kyu
    • Transactions of the Korean Society of Automotive Engineers
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    • v.14 no.6
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    • pp.73-81
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    • 2006
  • A commercial diesel engine was converted into a dedicated natural gas engine to reduce the exhaust emissions in a retrofit of a diesel-fueled vehicle. The cylinder head and piston were remodeled into engine parts suited for a spark ignition engine using natural gas. The remodeling of the combustion chamber changed the compression ratio from 21.5 to 10.5. A multi-point port injection(MPI) system for a dedicated natural gas engine was also adopted to increase the engine power and torque through improved volumetric efficiency, to allow a rapid engine response to changes in throttle position, and to control the precise equivalence ratio during cold-start and engine warm-up. The performance and exhaust emissions of the retrofitted natural gas engine after remodeling a diesel engine are investigated. The emissions of the retrofitted natural gas engine were low enough to satisfy the limits for a transitional low emission vehicle(TLEV) in Korea. We concluded that a diesel engine can be effectively converted into a dedicated natural gas engine without any deterioration in engine performance or exhaust emissions.

SI Engine Hydrocarbon Emissions Reduction with Secondary Air Injection and Coolant Control (2차 공기분사 및 냉각수제어에 의한 SI 엔진의 탄화수소 배기저감)

  • 박기수;조영진;박심수
    • Transactions of the Korean Society of Automotive Engineers
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    • v.8 no.4
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    • pp.51-58
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    • 2000
  • It is well known that the majority of the emissions measured from vehicle exhaust in the US Federal Test Procedure(FTP-75) are emitted during the first 60 seconds. This paper describes an experimental study on SI engine emissions reduction after cold start with interval secondary air injection and coolant control. Secondary air injection after cold start to reduce exhaust emissions causes an exothermic reaction at the exhaust port and gives sufficient air to the catalyst. For that reason engine-out emissions oxidized in the exhaust port and the rapid heating of a catalytic converter after cold start with CSAI and ISAI are estimated. The influence of the coolant temperature on SI engine emissions has been estimated. In the present studycoolant control of the cylinder head tempeature is used to investigate the effect of coolant temperature on SI engine emissions. The results show that engine-out hydrocarbon and carbon monoxide emissions are considerably reduced with interval secondary air injection and coolant control.

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An Experimental Study on the Metal Surface Temperature and Heat Transfer by Improving Gasoline Engine Cooling Passages (가솔린엔진의 냉각계 유로 변경을 통한 금속면 온도 및 전열에 관한 실험적 연구)

  • 이재헌;류택용;신승용;최재권
    • Transactions of the Korean Society of Automotive Engineers
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    • v.10 no.1
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    • pp.1-8
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    • 2002
  • Metal surface temperatures around the combustion chamber in a gasoline engine directly affect thermal durability and performance of the engine. Metal surface temperatures are influenced by many cooling factors such as drilled water passage, deflector, combustion chamber wall thickness, pillar, and coolant flow pattern. The object of this study is to learn how the coolant passages and coolant flow pattern in an engine influence to the engine metal surface temperature at engine full load and speed. From the test result, it is suggested a plan to reinforce the engine stiffness and to reduce the thermal stress simultaneously. Also, approaches are introduced to reduce the thermal load on the engine by adjusting the discharging direction from the water pump and by optimizing the water transfer holes in the cylinder head gasket. These methods and the optimized engine cooling system, which were suggested in this paper, were adapted for an engine in progress to eliminate the exhaust valve seat wear.

A Study on the Correlation of Oil Drain and Engine Tilting Angle (오일 드레인과 엔진경사각도간의 상관관계)

  • Kim, Dae-Yeol;Park, Pyong-Wan
    • Transactions of the Korean Society of Automotive Engineers
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    • v.19 no.5
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    • pp.51-57
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    • 2011
  • Parametric studies based on analysis of lubrication system of a four cylinder gasoline engine are illustrated system in this paper. In development process of engine lubrication system, parts of failure cases are related with oil pull over and oil churning phenomenon. The crankcase & head system pressure by oil churning phenomenon are gradual increased. It cause oil pull over phenomenon at engine breather line and oil over-consumption. In order to improve oil reduction and oil pull over phenomenon are also considered in the developing state. For this study, the characteristics of engine lubrication system are measured at various tilting angle and drain hole sizes. In addition, the oil flow & oil quantity are tested by blow by meter and catch jar. Results are presented to stabilize the oil supply system at sever driving condition. The data from present study are available for the engine lubrication system.