LES And URANS simulations of the swirling flow in a dynamic model of a uniflow-scavenged cylinder

Hemmingsen, Casper Schytte; Ingvorsen, Kristian Mark; Mayer, Stefan; Walther, Jens Honoré

doi:10.1016/j.ijheatfluidflow.2016.10.008

Cited by 7 publications

(5 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Large two-stroke marine diesel engines dominate as prime movers for cargo ships due to their high efficiency, low fuel consumption, and reliability [2]. The scavenging process delivers fresh air to the combustion chamber, removes combustion gases in the cylinder, cools the combustion chamber surfaces, and distributes fuel in the cylinder [3], playing an important role in the two-stroke marine engines. Therefore, the efficiency of the scavenging process is crucial for the total engine performance.…”

Section: Introductionmentioning

confidence: 99%

“…Therefore, computational fluid dynamics (CFD) studies are essential to obtain an understanding of the scavenging flow inside the large engine cylinder. There are several CFD studies of the scavenging flow in a model engine using Unsteady Reynolds Averaged Navier Stokes (URANS) and Large Eddy Simulation (LES) models [3,10,11,12,13]. However, three-dimensional (3D) CFD simulations on the large two-stroke engines are limited.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Numerical Study of the Scavenging Process in a Large Two-Stroke Marine Engine Using URANS and LES Turbulence Models

Nemati¹,

Ong²,

Jensen³

et al. 2020

SAE Technical Paper Series

Self Cite

View full text Add to dashboard Cite

 Users may download and print one copy of any publication from the public portal for the purpose of private study or research.  You may not further distribute the material or use it for any profit-making activity or commercial gain  You may freely distribute the URL identifying the publication in the public portal If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Numerical Study of the Scavenging Process in a Large Two-Stroke Marine Engine Using URANS and LES Turbulence Models

Nemati¹,

Ong²,

Jensen³

et al. 2020

SAE Technical Paper Series

Self Cite

View full text Add to dashboard Cite

show abstract

“…Although they found a good agreement with the measurements for both solutions, too, they stated a better prediction of the tangential velocity for LES [16]. Very similar results were found for an uniflow-scavenged cylinder in [17] and for an optical engine in [18]. Liu compared an axisymmetric piston-cylinder assembly with and without swirl flow and came to the conclusion that neither URANS nor LES provided a completely satisfying representation of the measurements with advantages for the more expensive LES [19].…”

Section: Basic Challenges Of Turbulent In-cylinder Flowmentioning

confidence: 72%

Towards a Predictive Simulation of Turbulent Combustion?—An Assessment for Large Internal Combustion Engines

Lauer

Frühhaber

2020

Energies

View full text Add to dashboard Cite

Frequently the question arises in what sense numerical simulation can be considered predictive if prior model tuning with test results is necessary. In this paper a summary of the present Computational Fluid Dynamics (CFD) simulation methods for in-cylinder modelling is presented with a focus on combustion processes relevant for large engines. The current discussion about the sustainability of internal combustion engines will have a strong impact on applying advanced CFD methods in industrial processes. It is therefore included in the assessment. Simplifications and assumptions of turbulence, spray, and combustion models, as well as uncertainties of model boundary conditions, are discussed and the future potential of an advanced approach like Large Eddy Simulation (LES) is evaluated. It follows that a high amount of expertise and a careful evaluation of the numerical results will remain necessary in the future to apply the best-suited models for a given combustion process. New chemical mechanisms will have to be developed in order to represent prospective fuels like hydrogen or OME. Multi-injection or dual fuel combustion will further pose high requirements to the numerical methods. Therefore, the further development and validation of advanced mixture, combustion and emission models will remain important. Close cooperation between academia, code suppliers and engine manufacturers could promote the necessary progress.

show abstract

“…Nevertheless, for most of the cases, the URANS approach offered reasonable results to describe the fluid flow for higher engine speeds and a higher Reynolds number [33]. On the other hand, as discussed in [34], most URANS models are poor in recreating the swirling flow in steady-flow configurations, while the LES model offers better results. Nonetheless, as mentioned in [35,36], LES applications are not straightforward due to the need for specific boundary conditions and severe grid resolutions/quality compared to RANS.…”

Section: Reynolod-average Navier-stokes Formalism and Turbulence Modelmentioning

confidence: 88%

Investigation of the Aerodynamic Performance of the Miller Cycle from Transparent Engine Experiments and CFD Simulations

et al. 2022

View full text Add to dashboard Cite

This paper assesses the effect of the Miller cycle upon the internal aerodynamics of a motored transparent spark ignition engine via CFD simulation and particle image velocimetry. Since the transparent Miller engine does not allow for measurements in the roof of the combustion chamber, the extraction of information regarding the aerodynamic phenomena occurring here is based on CFD simulation, i.e., the results of the CFD simulation are used to allow for the extrapolation of the experimental data; thus, they are used to complete the picture regarding the aerodynamic phenomena occurring inside the whole cylinder. The results indicate that implementing the early intake valve closing strategy to obtain the Miller cycle has a negative impact on the mean kinetic energy, turbulent kinetic energy, and fluctuating velocity toward the end of the compression stroke, thus affecting, the combustion process. This supports the need to intensify the internal aerodynamics when applying the Miller cycle such that the turbulence degradation is not too big and, consequently, to still gain efficiency in the Miller cycle.

show abstract

LES And URANS simulations of the swirling flow in a dynamic model of a uniflow-scavenged cylinder

Cited by 7 publications

References 20 publications

Numerical Study of the Scavenging Process in a Large Two-Stroke Marine Engine Using URANS and LES Turbulence Models

Numerical Study of the Scavenging Process in a Large Two-Stroke Marine Engine Using URANS and LES Turbulence Models

Towards a Predictive Simulation of Turbulent Combustion?—An Assessment for Large Internal Combustion Engines

Investigation of the Aerodynamic Performance of the Miller Cycle from Transparent Engine Experiments and CFD Simulations

Contact Info

Product

Resources

About