High-Speed Flow and Combustion Visualization to Study the Effects of Charge Motion Control on Fuel Spray Development and Combustion Inside a Direct-Injection Spark-Ignition Engine

Mittal, Mayank; Hung, David L.S.; Zhu, Guoming; Schock, Harold

doi:10.4271/2011-01-1213

Cited by 14 publications

(2 citation statements)

References 9 publications

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“…In-cylinder flow structures generated during the intake stroke and modified during the compression stroke can be divided into two main forms of large scale motions (coherent structures), swirl and tumble. Swirl is the in-cylinder flow where the flow rotational axis is parallel to the cylinder axis while tumble is the flow with an axis perpendicular to that of the cylinder [3][4][5]. These coherent structures are mainly relying on the bore/stroke ratio, intake valve geometry, inlet port profile and the shape of the combustion chamber [6][7][8][9].…”

Section: Introductionmentioning

confidence: 99%

On the Application of Proper Orthogonal Decomposition (POD) for In-Cylinder Flow Analysis

et al. 2018

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Proper orthogonal decomposition (POD) is a coherent structure identification technique based on either measured or computed data sets. Recently, POD has been adopted for the analysis of the in-cylinder flows inside internal combustion engines. In this study, stereoscopic particle image velocimetry (Stereo-PIV) measurements were carried out at the central vertical tumble plane inside an engine cylinder to acquire the velocity vector fields for the in-cylinder flow under different experimental conditions. Afterwards, the POD analysis were performed firstly on synthetic velocity vector fields with known characteristics in order to extract some fundamental properties of the POD technique. These data were used to reveal how the physical properties of coherent structures were captured and distributed among the POD modes, in addition to illustrate the difference between subtracting and non-subtracting the ensemble average prior to conducting POD on datasets. Moreover, two case studies for the in-cylinder flow at different valve lifts and different pressure differences across the air intake valves were presented and discussed as the effect of both valve lifts and pressure difference have not been investigated before using phase-invariant POD analysis. The results demonstrated that for repeatable flow pattern, only the first mode was sufficient to reconstruct the physical properties of the flow. Furthermore, POD analysis confirmed the negligible effect of pressure difference and subsequently the effect of engine speed on flow structures.

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Section: Introductionmentioning

confidence: 99%

On the Application of Proper Orthogonal Decomposition (POD) for In-Cylinder Flow Analysis

et al. 2018

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“…flame propagation which would significantly improve engine performance. The two dominant in-cylinder flow processes -namely, tumble flow and swirl flow -have been studied for decades by numerous researchers [4][5][6][7]. In addition to the flow introduced by charge motion, the motions of engine piston and exhaust valve [8], and flow pulsation [9], are also considered to be critical factors influencing the in-cylinder flow characteristics.…”

Section: Introductionmentioning

confidence: 99%

Characterization of the effect of intake air swirl motion on time-resolved in-cylinder flow field using quadruple proper orthogonal decomposition

Zhuang

Hung

2016

Energy Conversion and Management

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a b s t r a c tThe control of intake air swirl motion is often used in spark-ignition direct-injection (SIDI) engine to improve its in-cylinder fuel-air mixing process especially under engine idle and low load conditions. In this experimental investigation, a novel technique combining the time-resolved particle image velocimetry (PIV) with quadruple proper orthogonal decomposition (POD) is implemented to analyze the time-resolved in-cylinder velocity measurements in an optically-accessible SIDI engine. The intake air swirl motion is introduced into the engine cylinder by a control valve installed in one of two air intake ports. Experimental results show that a strong linear correlation exists between the intake flow swirl ratio and vorticity flow field in the cylinder. This correlation ensures high data reliability of swirl motion control and provides a novel basis to directly compare the flow field measurements under different swirl ratio conditions. The quadruple proper orthogonal decomposition analysis is then applied to the velocity flow fields to separate the highly dynamic in-cylinder flow characteristics into four distinct categories: (1) dominant flow structure; (2) coherent structure; (3) turbulent structure; and (4) noise structure. The results show that the dominant flow structure varies strongly with swirl ratio, and its kinetic energy is also directly related to the swirl ratio. The coherent structure captures the large scale flow characteristics, but its kinetic energy is much lower and exhibits larger cycle-to-cycle variations. The turbulent structure contains similar level of kinetic energy at different swirl ratios but without much cycle-to-cycle variation. Finally, the noise structure contains very low kinetic energy which only alters the dynamic nature of the flow field slightly. In summary, the effect of swirl ratio on in-cylinder flow field is mostly captured by the dominant flow structure and partially captured by the coherent flow structure. The turbulent flow structure can characterize the high-order flow variation. The noise structure can be neglected due to the low energy captured.

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Experimental Investigation on Fuel Spray Optimization in Gasoline Direct Injection Engine

Bo¹,

Pan²,

Liu³

et al. 2012

Lecture Notes in Electrical Engineering

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High-Speed Flow and Combustion Visualization to Study the Effects of Charge Motion Control on Fuel Spray Development and Combustion Inside a Direct-Injection Spark-Ignition Engine

Cited by 14 publications

References 9 publications

On the Application of Proper Orthogonal Decomposition (POD) for In-Cylinder Flow Analysis

On the Application of Proper Orthogonal Decomposition (POD) for In-Cylinder Flow Analysis

Characterization of the effect of intake air swirl motion on time-resolved in-cylinder flow field using quadruple proper orthogonal decomposition

Experimental Investigation on Fuel Spray Optimization in Gasoline Direct Injection Engine

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