Influence of Swirl and Tumble on Economy and Emissions of Multi Valve SI Engines

Endres, H.; Neuβer, H.-J.; Wurms, Rainer

doi:10.4271/920516

Cited by 39 publications

(12 citation statements)

References 1 publication

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“…This will favor gaseous fuels over gasoline, and application of advanced techniques such as high in-cylinder turbulence, variable valve timing, and variable intake geometry. (8)(9)(10).…”

Section: B Four-stroke Spark-ignited Enginesmentioning

confidence: 99%

A Survey of Technology for Hybrid Vehicle Auxiliary Power Units.

Widener¹

1995

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“…This will favor gaseous fuels over gasoline, and application of advanced techniques such as high in-cylinder turbulence, variable valve timing, and variable intake geometry. (8)(9)(10).…”

Section: B Four-stroke Spark-ignited Enginesmentioning

confidence: 99%

A Survey of Technology for Hybrid Vehicle Auxiliary Power Units.

Widener¹

1995

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“…As a result, the shape and the relative position of the intake port usually deviate from its original design. These deviations may change the swirl ratio (Rs) and mean flow coefficient (C/m) and lead to worse mixture forma tion and combustion processes, consequently deteriorating engine performance [8][9][10][11][12][13]. To achieve the desired flow characteristics in the intake port, higher tolerance is needed during the production process.…”

Section: Introductionmentioning

confidence: 98%

Experimental and Modeling Study of the Effect of Manufacturing Deviations on the Flow Characteristics of Tangential Intake Port in a Diesel Engine

Wang

Liu

et al. 2014

Journal of Engineering for Gas Turbines and Power

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The intake port flow characteristics in an internal combustion engine significantly affect its power output, fuel economy, and emissions. To optimize the flow characteristics in the intake port, increasing attention has been paid to its design process. However, the casting and machining processes of the intake port are underappreciated, which may introduce significant deviations, leading to undesirable variation of intake port flow and subsequent deterioration in engine combustion and emissions. In this paper, steady flow tests were carried out on a four-valve diesel engine to investigate how and to what extent the casting and machining deviations of the intake port influence the in-cylinder flow characteristics. The results show that these deviations lead to the variation of swirl ratio up to 20%. Then, computational fluid dynamics (CFD) simulation was conducted for understanding the reason. It is indicated that higher tolerance is needed during the cast ing and machining processes. For example, in order to control the variation o f swirl ratio within 10%, the inclined angle should be controlled at less than 1 deg, the eccentric dis tance should be restricted to less than 0.5 mm, and the swelling thickness should be lim ited to less than 1 mm.

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“…Instead of shrouded valves, the tumbling motion can be achieved by using directed ports [7]. It was shown [8][9][10] that with the appearance of the tumbling vortex in modern multivalve engines the burning rate is sped up while emissions are reduced. In addition, the lean burn limit is extended.…”

Section: Introductionmentioning

confidence: 98%

Tumbling/Squish Interaction in Loop-Scavenged Two-Stroke Engines

Tsui

Cheng

1997

Numerical Heat Transfer, Part A: Applications

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This anide describes a numerical investigation of the flow in a loop-scavenged two-stroke engine equipped with a head-bowl combustion chamber. The bowl is either plautl in the center of the cylinder head or displaced away from the center. A1Iention is focused on the period of compression and early expansion. Resulss show that the effects of compression of the tumbling vortex by the piston become prominent after the midcompression slage, resulting in significant cascading of energy from mean flow to turbulence, followed by a fast decay ofturbaJence. The subsequent emergence ofsquish and reverse squish helps retard the decay. As a consequence, the cases with head bowls possess higher levels of mean flow and turbulence than those withoul bowls at top dead center and the later slage. It is also shawn in the resu/ls that the offset of the head bowt has signifICant effects on the mean flow and turbulence characteristics, highly dependent on the offset direction.

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Influence of Swirl and Tumble on Economy and Emissions of Multi Valve SI Engines

Cited by 39 publications

References 1 publication

A Survey of Technology for Hybrid Vehicle Auxiliary Power Units.

A Survey of Technology for Hybrid Vehicle Auxiliary Power Units.

Experimental and Modeling Study of the Effect of Manufacturing Deviations on the Flow Characteristics of Tangential Intake Port in a Diesel Engine

Tumbling/Squish Interaction in Loop-Scavenged Two-Stroke Engines

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