Use of proper orthogonal decomposition for time interpolation from PIV data

Druault, Philippe; Guibert, Philippe; Alizon, Franck

doi:10.1007/s00348-005-0035-3

Cited by 145 publications

(57 citation statements)

References 20 publications

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“…To classify the turbulent characteristics of the flow, we consider the turbulent kinetic energy as calculated from the stereoscopic PIV data based on phase averaging similar to many previous studies on engine flows (for example, Druault et al, 2005;Müller et al, 2010). An instantaneous velocity component ( , ) is decomposed into a phase-averaged part ̅( ) and a fluctuating part ′( , ) given by …”

Section: Resultsmentioning

confidence: 99%

Experimental and numerical investigation of a pulsatile flow field in an S-shaped exhaust pipe of an automotive engine

Oki

Ikeguchi

Ogata

et al. 2017

JFST

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A pulsatile turbulent flow within an S-shaped double bend pipe is experimentally and numerically studied to characterize the flow field in conditions resembling an automotive engine environment. Particle image velocimetry (PIV) measurements were carried out to measure streamwise and secondary flow velocities. The flows are accelerated around the inner side walls of both bends. The secondary flow, after passing through the second bend, is directed toward the inner side in the core of the cross section, and, as a result, Lyne-type vortices, which are not consistent with the second bend curvature, are formed. A numerical simulation is performed under the same condition as the experiments with computational fluid dynamics software. The numerical simulation gives qualitative results in comparison with the experimental data though there is some deviation, and shows the cause of the Lyne-type vortex formation in the second bend. After passing through the first bend, the high-speed region appearing around the inner side shifts in accordance with the Dean-type secondary flow formed in the first bend, and thus the non-uniform flow enters the second bend. In the second bend, the low-velocity region in which the centrifugal force is not strong enough to direct the flow toward the outer side, appears in the core of the cross section. Details of the Lyne-type vortex formation are discussed by considering the driving forces of the secondary flow.

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Section: Resultsmentioning

confidence: 99%

Experimental and numerical investigation of a pulsatile flow field in an S-shaped exhaust pipe of an automotive engine

Oki

Ikeguchi

Ogata

et al. 2017

JFST

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“…However, the general outcome is that this approach is not able to reconstruct past the Nyquist limit. For example, a proper orthogonal decomposition (POD) based method proposed by Druault et al (2005) has successfully reconstructed the large-scale dynamical evolution of a tumbling vortex inside an internal combustion engine. Such reconstructions are however possible only within the hypothesis of flow quasi-periodicity and are only valid for the largescale structures of the flow (Bouhoubeiny and Druault 2009).…”

Section: Introductionmentioning

confidence: 99%

Time-supersampling of 3D-PIV measurements with vortex-in-cell simulation

2014

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The present work investigates the use of a numerical approximation to the Navier-Stokes equations to increase the temporal resolution of time-resolved PIV data for general flows. The solution of the governing equations is applied to 3D data obtained from tomographic PIV and is based on the vortex-in-cell method (Christiansen in J Comput Phys 13: [363][364][365][366][367][368][369][370][371][372][373][374][375][376][377][378][379] 1973) under the hypothesis of incompressible flow. The principle of time-supersampling is that the spatial information can be leveraged to increase the temporal resolution. The unsteady numerical simulation of the dynamic evolution of the flow is applied within the 3D measurement domain and time integration is performed between each pair of consecutive measurements. Initial conditions are taken from the first measurement field and time-resolved boundary conditions are approximated between the two fields. Temporal continuity of the velocity field is obtained by imposing a weighted average of forward and backward time integration. The accuracy of this time-supersampling method is studied for two experimental datasets obtained from time-resolved tomographic PIV measurements: a turbulent wake and a circular jet. The results are compared to linear interpolation, advectionbased supersampling, and measurement data at high sampling rate. In both flows, we demonstrate the ability to reconstruct detailed temporal dynamics using data subsampled at a rate far below the Nyquist frequency.

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“…Furthermore, the low frequency fluctuation energy accounted for about 90% of the total fluctuation kinetic energy. The proportion of fluctuation kinetic energy to the total velocity energy is higher than that obtained by Druault et al [25], and some of the reason is that the engine speed was set lower in the present study, which may enhance the velocity fluctuation [26]. Moreover, the energies of the flow fields were enhanced largely as the MVL was decreased, which can be seen by comparing the same kind of energy curves at the different MVL conditions.…”

Section: Effects Of Maximum Valve Lifts On Fluctuating Kinetic Energymentioning

confidence: 43%

Effects of Variable Valve Lift on In-Cylinder Air Motion

et al. 2015

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An investigation into in-cylinder swirl and tumble flow characteristics with reduced maximum valve lifts (MVL) is presented. The experimental work was conducted in the modified four-valve optical spark-ignition (SI) test engine with three different MVL. Particle image velocimetry (PIV) was employed for measuring in-cylinder air motion and measurement results were analyzed for examining flow field, swirl and tumble ratio variation and fluctuating kinetic energy distribution. Results of ensemble-averaged flow fields show that reduced MVL could produce strong swirl flow velocity, then resulted in very regular swirl motion in the late stage of the intake process. The strong swirl flow can maintain very well until the late compression stage. The reduction of MVL can also increase both high-frequency and low-frequency swirl flow fluctuating kinetic energy remarkably. Regarding tumble flow, results demonstrate that lower MVLs result in more horizontal intake flow velocity vectors which can be easily detected under the valve seat area. Although the result of lower MVLs show a higher tumble ratio when the piston is close to the bottom dead centre (BDC), higher MVLs substantially produce higher tumble ratios which can be confirmed when most cylinder area lies in the measuring range.

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Use of proper orthogonal decomposition for time interpolation from PIV data

Cited by 145 publications

References 20 publications

Experimental and numerical investigation of a pulsatile flow field in an S-shaped exhaust pipe of an automotive engine

Experimental and numerical investigation of a pulsatile flow field in an S-shaped exhaust pipe of an automotive engine

Time-supersampling of 3D-PIV measurements with vortex-in-cell simulation

Effects of Variable Valve Lift on In-Cylinder Air Motion

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