Valve Events and Engine Operation

Asmus, Thomas W.

doi:10.4271/820749

Cited by 38 publications

(4 citation statements)

References 12 publications

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“…Most studies in the field of VVT technology deal with valves timing optimization during steady-state condition. Some of them are included in the references [2][3][4][5][6][7][8][9][10][11]. Some studies are related to analysis of the transient performance of spark ignition engines; however, less attention is paid to study of simultaneous effect of valve's four events variations and waste gate effective diameter on the transient response.…”

Section: Introductionmentioning

confidence: 99%

Simultaneous dynamic optimization of valves timing and waste gate to improve the load step transient response of a turbocharged spark ignition engine

Kakaee

Keshavarz

2017

J Braz. Soc. Mech. Sci. Eng.

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Section: Introductionmentioning

confidence: 99%

Simultaneous dynamic optimization of valves timing and waste gate to improve the load step transient response of a turbocharged spark ignition engine

Kakaee

Keshavarz

2017

J Braz. Soc. Mech. Sci. Eng.

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“…The reason is due to the typical IVO timing is about 0 to 10 degrees before the TDC, which results in a reasonably symmetrical overlap of the valve around the TDC [12]. Next, Asmus [23] states that further delay in the IVO causes the cylinder pressure to dip momentarily below the intake manifold pressure. It also states that the timing of IVC is the single most important determinant of the equilibrium of low-speed and high-speed volumetric efficiency.…”

Section: Simulation Modelmentioning

confidence: 99%

The Influence of Valve Timing on in-Cylinder Pressure Spark Ignition Engines Performance Characteristics

Pahmi,

Mustaffa,

Basri

et al. 2023

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The performance of the engine depends on many factors. One of the factors is valve timing known to be the timing of opening and closing of valves that has a significant effect on the in-cylinder performance. However, there is less information in the study about valve timing effect on single cylinder engine performances. In this study, the focus is to analyze in-cylinder pressure characteristics on a single piston fuel injection for a spark-ignition engine. This can be done by simulating the effects of valve timing on in-cylinder pressure. The methodology of this project will be simulation-based by using commercial one-dimensional software. The research results are engine performance parameters which are volumetric efficiency, brake torque, brake power, and cylinder pressure in 1000 to 5500 RPM engines. The results show a positive increment in engine performance from the baseline model (CTA240) which is 9.06% for brake power, 2.85% for brake torque, and 13.09% for volumetric efficiency. At low engine speed, it was also found improvement in cylinder pressure when advancing the intake valve timing opening (IVO) by 20 to 25 degrees bTDC. For high speed, the cylinder pressure was found to improve once the retardation of intake valve timing closing (IVC) was done between 40 to 45 degrees aBDC by comparing it with the baseline results. The result highlights the importance of intake valve timing setup by varying the opening and closing of the intake valve to give better output for engine performance.

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“…LIVC strategy present difficulties because early ignition can occur before intake valve has been closed at very low loads [7]. Asmus [8] explained that volumetric efficiency increases by delaying the intake valve closing at higher speed with the risk of charge reverse flow. Similar observation was made by Neher [9], which resulted in poor engine efficiency due to reverse flow occurs during compression stroke that later cause loss during compression.…”

Section: Introductionmentioning

confidence: 99%

The tuning of a small four-stroke spark ignition engine for flexible valve timings through numerical approach

2019

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Variable valve timing has been implemented by various manufacturers to improve internal combustion engine performance while operating at wide speed and load ranges. A novel flexible valve timing system for a small four-stroke engine is currently under development by Automotive Engineering Research Group (AERG) in Universiti Malaysia Pahang (UMP). In this paper, a comprehensive intake and exhaust tuning for the flexible variable valve timing is presented. A numerical assessment has been conducted through one dimensional engine modelling and simulation using validated model. There are eight valve timing configurations investigated for the tuning for three main speed regions. The simulation shows a positive and significant impact to the engine performance in three approaches; namely late intake valve closing, early intake valve closing and late exhaust valve closing. These approaches sufficiently covered the whole range of engine speeds for optimum engine operational performance.

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Valve Events and Engine Operation

Cited by 38 publications

References 12 publications

Simultaneous dynamic optimization of valves timing and waste gate to improve the load step transient response of a turbocharged spark ignition engine

Simultaneous dynamic optimization of valves timing and waste gate to improve the load step transient response of a turbocharged spark ignition engine

The Influence of Valve Timing on in-Cylinder Pressure Spark Ignition Engines Performance Characteristics

The tuning of a small four-stroke spark ignition engine for flexible valve timings through numerical approach

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