Investigation of Sub-Grid Model Effect on the Accuracy of In-Cylinder LES of the TCC Engine under Motored Conditions

Ko, Insuk; Min, Kyoungdoug; Rulli, Federico; D'Adamo, Alessandro; Berni, Fabio; Fontanesi, Stefano

doi:10.4271/2017-24-0040

Cited by 16 publications

(13 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The bore × stroke values are equal to 92 × 86mm, with a (nominal) compression ratio of 10:1. This engine has already been the object of extensive numerical studies by the authors [26,27,35,36], in which the zonal hybrid methodology shown above has been implemented into the STAR-CD software [37] and then assessed and validated on a relatively fine computational grid (2×10 6 elements at the BDC). Nonetheless, a head-to-head comparison between the DES and DESx modes of operation was still missing and is, therefore, proposed here.…”

Section: Zonal-des Implementationmentioning

confidence: 99%

Standard and consistent Detached-Eddy Simulation for turbulent engine flow modeling: an application to the TCC-III engine

et al. 2020

Self Cite

View full text Add to dashboard Cite

Multidimensional modeling of Cycle-to-Cycle Variability (CCV) has become a crucial support for the development and optimization of modern direct-injection turbocharged engines. In that sense, the only viable modeling options is represented by scale-resolving approaches such as Large Eddy Simulation (LES) or hybrid URANS/LES methods. Among other hybrid approaches, Detached-Eddy Simulation (DES) has the longest development story and is therefore commonly regarded as the most reliable choice for engineering-grade simulation. As such, in the last decade DESbased methods have found their way through the engine modeling community, showing a good potential in describing turbulence-related CCV in realistic engine configurations and at reasonable computational costs. In the present work we investigate the in-cylinder modeling capabilites of a standard two-equation DES formulation, compared to a more recent one which we call DESx. The DESx form differs from standard DES in the turbulent viscosity switch from URANS to LES-like behavior, which for DESx is fully consistent with Yoshizawa’s one-equation sub-grid scale model. The two formulations are part of a more general Zonal-DES (ZDES) methodology, developed and validated by the authors in a series of previous publications. Both variants are applied to the multi-cycle simulation of the TCC-III experimental engine setup, using sub-optimal grid refinement levels in order to stress the model limitations in URANS-like numerical resolution scenarios. Outcomes from this study show that, although both alternatives are able to ouperform URANS even in coarse grid arrangements, DESx emerges as sligthly superior and thus it can be recommended as the default option for in-cylinder flow simulation.

show abstract

Section: Zonal-des Implementationmentioning

confidence: 99%

Standard and consistent Detached-Eddy Simulation for turbulent engine flow modeling: an application to the TCC-III engine

et al. 2020

Self Cite

View full text Add to dashboard Cite

show abstract

“…In addition, it has already been the object of extensive LES studies at the University of Modena and Reggio Emilia ICE research group. 25,26…”

Section: Tcc-iii Engine Casementioning

confidence: 99%

“…The use of differently populated datasets does not impact the validity of the comparison as demonstrated by the authors in a previous work. 26 Additional quantities such as turbulent scalars are also sampled and averaged to further dissect the turbulence modeling performance. A side-by-side comparison is made against both the reference experimental measurements and an earlier full-LES simulation campaign carried out with the dynamic structure model ( DSM ).…”

Section: Tcc-iii Engine Casementioning

confidence: 99%

See 1 more Smart Citation

Validation of a zonal hybrid URANS/LES turbulence modeling method for multi-cycle engine flow simulation

Krastev

D'Adamo

Berni

et al. 2019

International Journal of Engine Research

Self Cite

View full text Add to dashboard Cite

A zonal hybridization of the RNG [Formula: see text]-[Formula: see text] URANS model is proposed for the simulation of turbulent flows in internal combustion engines. The hybrid formulation is able to act as URANS, DES or LES in different zones of the computational domain, which are explicitly set by the user. The resulting model has been implemented in a commercial computational fluid dynamics code and the LES branch of the modified RNG [Formula: see text]-[Formula: see text] closure has been initially calibrated on a standard homogeneous turbulence box case. Subsequently, the full zonal formulation has been tested on a fixed intake valve geometry, including comparisons with third-party experimental data. The core of the work is represented by a multi-cycle analysis of the TCC-III experimental engine configuration, which has been compared with the experiments and with prior full-LES computational studies. The applicability of the hybrid turbulence model to internal combustion engine flows is demonstrated, and PIV-like flow statistics quantitatively validate the model performance. This study shows a pioneering application of zonal hybrid models in engine-relevant simulation campaigns, emphasizing the relevance of hybrid models for turbulent engine flows.

show abstract

“…POD has been applied to in-cylinder velocity data of reciprocating engines by a number of groups. [19][20][21][22][23][24] Graftieaux et al 25 suggested using POD to separate pseudo-fluctuations attributed to the unsteady nature of the large-scale vortices from fluctuations caused by small-scale turbulence. Chen et al 26 proposed a practical guide to apply POD in ICE research.…”

Section: Introductionmentioning

confidence: 99%

A critical review of flow field analysis methods involving proper orthogonal decomposition and quadruple proper orthogonal decomposition for internal combustion engines

Rulli

Fontanesi

D'Adamo

et al. 2019

International Journal of Engine Research

Self Cite

View full text Add to dashboard Cite

Experimental techniques like particle image velocimetry provide a powerful technical support for the analysis of the spatial and temporal evolution of the flow field in internal combustion engines. Such techniques can be used to investigate both ensemble-averaged flow structures and their cyclic variations. These last are among the major causes of cycle-to-cycle variability of the engine processes (mixture formation, combustion, heat transfer, emission formation), the reduction of which has become a paradigm recently in engine development. Proper orthogonal decomposition has been largely used in conjunction with particle image velocimetry to analyze flow field characteristics. Several methods involving proper orthogonal decomposition have been proposed in the recent years to analyze engine cycle-to-cycle variability. In this work, phase-invariant proper orthogonal decomposition analysis, conditional averaging and triple and quadruple proper orthogonal decomposition methods are first introduced and applied to a large database of particle image velocimetry data from a well-known research engine. Results are discussed with particular emphasis on the capability of the methods to perform both quantitative and qualitative evaluations on cycle-to-cycle variability. Second, a new quadruple proper orthogonal decomposition methodology is proposed and compared to those available in the literature. All the methods are found to be helpful to identify the turbulent structures responsible for cycle-to-cycle variability. They can be equally applied to both experimental and numerical datasets to analyze turbulent fields in detail and to make comparisons.

show abstract

Investigation of Sub-Grid Model Effect on the Accuracy of In-Cylinder LES of the TCC Engine under Motored Conditions

Cited by 16 publications

References 33 publications

Standard and consistent Detached-Eddy Simulation for turbulent engine flow modeling: an application to the TCC-III engine

Standard and consistent Detached-Eddy Simulation for turbulent engine flow modeling: an application to the TCC-III engine

Validation of a zonal hybrid URANS/LES turbulence modeling method for multi-cycle engine flow simulation

A critical review of flow field analysis methods involving proper orthogonal decomposition and quadruple proper orthogonal decomposition for internal combustion engines

Contact Info

Product

Resources

About