Proper orthogonal decomposition analysis for cycle-to-cycle variations of engine flow. Effect of a control device in an inlet pipe

Vu, Trung-Thanh; Guibert, Philippe

doi:10.1007/s00348-012-1268-6

Cited by 41 publications

(25 citation statements)

References 43 publications

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“…Recently, some researchers used the POD method to separate the in-cylinder flow into different field parts, and then studied the characteristics of each part separately. By doing so, they obtained more insightful details of the in-cylinder flow field [37][38][39].…”

Section: Introductionmentioning

confidence: 97%

Investigation of the temporal evolution and spatial variation of in-cylinder engine fuel spray characteristics

Qin

Hung

2015

Energy Conversion and Management

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Section: Introductionmentioning

confidence: 97%

Investigation of the temporal evolution and spatial variation of in-cylinder engine fuel spray characteristics

Qin

Hung

2015

Energy Conversion and Management

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“…For example, Druault et al made a POD analysis of PIV data to understand the variability change during an engine cycle [21]. Vu and Guibert focused on variations inside the engine occurring with modification of the inlet pipe [22]. Graftieaux et al [14] and Zhuang et al [23] introduced POD into vortex analysis to study the flow field characteristics in motoring optical engines.…”

Section: Introductionmentioning

confidence: 99%

“…This investigation demonstrates a first attempt to reveal the impact of intake swirl ratio (SR) on incylinder engine flow using the quadruple POD analysis technique. The concept is derived by reconstructing classical POD modes of similar features into several groups to better represent the flow field properties [22,24,29]. In a classical POD analysis, the first mode usually contains the dominant flow characteristic; then the remaining higher modes only show limited differences in kinetic energy among each other, which has led to an imprecise determination of the properties of individual mode.…”

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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“…In this paper, proper orthogonal decomposition (POD) was used to quantify the cycle-to-cycle flow variations within individual data sets and evaluate potential causes. POD has been used in previous studies to differentiate between cycle-to-cycle flow variations and turbulence by choosing a cut-off mode, with lower order modes being used to reconstruct the cycle-to-cycle flow variations and higher order modes used to reconstruct the turbulence 1,11 . However, Cosadia et al 12 found that determining a cut-off mode was not possible, as the cumulative energy fractions of the POD of the instantaneous velocity fields converged very slowly despite the presence of a strong in-cylinder swirl motion.…”

Section: Introductionmentioning

confidence: 99%

Flow-pattern switching in a motored spark ignition engine

Abraham

Yang

Gupta

et al. 2015

International Journal of Engine Research

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Cycle-to-cycle variability of intake-jet flow in an optical engine was measured using particle image velocimetry, revealing the possibility of two different flow patterns. A phase-dependent proper orthogonal decomposition analysis showed that one or the other flow pattern would appear in the average flow, sampled from test to test or sub-sampled within a single test; each data set contained individual cycles showing one flow pattern or the other. Three-dimensional velocity data from a large-eddy simulation of the engine showed that the particle image velocimetry plane cuts through a region of high shear between the intake jet and another large flow structure. Rotating the measurement plane 610°revealed one or the other flow structure observed in the particle image velocimetry measurements. Thus, it was hypothesized that cycle-to-cycle variations in the swirl ratio result in the two different flow patterns in the particle image velocimetry plane. Having an unambiguous metric to reveal large-scale flow cycle-to-cycle variability, causes for this variability were examined within the possible sources present in the available testing. In particular, variations in intake-port and cylinder pressure, lateral valve oscillations, and engine RPM were examined as potential causes for the cycle-to-cycle flow variations using the phase-dependent proper orthogonal decomposition coefficients. No direct correlation was seen between the intake-port pressure, or the pressure drop across the intake valve, and the in-cylinder flow pattern. A correlation was observed between dominant flow pattern and cycle-to-cycle variations in intake-valve horizontal position. RPM values and in-cylinder flow patterns did not correlate directly. However, a shift in flow pattern was observed between early and late cycles in a 2900-cycle test after an approximately 5 r/min engine speed perturbation.

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Proper orthogonal decomposition analysis for cycle-to-cycle variations of engine flow. Effect of a control device in an inlet pipe

Cited by 41 publications

References 43 publications

Investigation of the temporal evolution and spatial variation of in-cylinder engine fuel spray characteristics

Investigation of the temporal evolution and spatial variation of in-cylinder engine fuel spray characteristics

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

Flow-pattern switching in a motored spark ignition engine

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