Development of quasi-dimensional turbulence model for spark-ignition engine with physical analysis of tumble: Energy-based tumble model focusing on energy intake and turbulence production

Kim, Myoungsoo; Kim, Yirop; Kim, Joohan; Song, Han Ho

doi:10.1016/j.apenergy.2019.113455

Cited by 11 publications

(12 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The turbulence production model is based on the previous study 11 while undergoing some modifications on the correcting factor n. This model utilizes a 3D virtual velocity field to reproduce the decaying rate of tumble energy at the designated cylinder geometry. Since the model constructs a virtual velocity field at a given amount of mean kinetic energy, we can straightforwardly calculate the decaying rates at the specified cylinder bore and height.…”

Section: Discussionmentioning

confidence: 99%

“…Concerning the speed of intake gas, as can be identified in equations ( 11) and ( 12), the kinetic energy loss, which is equivalent to _ K nonrot , increases as the rate of change of kinetic energy intake increases at a given value of the loss coefficient; the kinetic energy loss is set proportional to the squared velocity of intake gas. Accordingly, it can be concluded that the loss attributed to the speed of intake gas is reflected priorly in equation (11). Therefore, other losses irrelevant to the speed of intake gas will be discussed and reflected in the loss coefficient.…”

Section: Intake Model With Flow Dynamics Analysismentioning

confidence: 99%

“…The model is primarily developed by the virtual velocity field imitating the tumble structure. The velocity field, called the ''barrel swirl'' function, was first proposed by Benjamin 26 and later modified by Kim et al 11 to reflect the vortex breakdown of tumble. The equations for modified barrel swirl is given as…”

Section: Turbulence Production Modelmentioning

confidence: 99%

“…Due to its importance, extensive research has been conducted to investigate the factors influencing tumble numerically 4,10,11 and experimentally. 4,[12][13][14][15] Considering discrete engine geometries influence the formation of tumble, several studies were conducted to control tumble strength using various piston shapes 10,12 and engine port designs.…”

Section: Introductionmentioning

confidence: 99%

“…4,16 Besides, given that tumble varies depending on the operating conditions, experimental studies with variable valve actuation strategies (e.g. shifting valve lift 15 and valve timing 13 ) and different engine speeds 11,14 were conducted to identify their effect on tumble.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

A universally applicable 0D turbulence model based on the physical analysis of fundamental tumble behaviors in spark-ignition engines

Kim

Song

2022

International Journal of Engine Research

Self Cite

View full text Add to dashboard Cite

Predicting turbulence in a zero-dimensional (0D) simulation is an undeniably challenging task due to the complexity of in-cylinder charge motion. In that respect, a physics-based understanding of in-cylinder flow phenomena is of vital importance for establishing high-fidelity 0D turbulence models under diverse engine conditions. The proposed 0D model is hence built upon the kinetic energy analyses of tumble, evidenced by three-dimensional computational fluid dynamics. Specifically, the overall 0D turbulence model consists of an intake model, a spinning up model, and a turbulence production model. The major difference between this model and the existing 0D turbulence models is that this model is grounded on a kinetic energy perspective of tumble, as opposed to an angular momentum perspective of tumble. That is, the behaviors of tumble, such as spinning up and vortex breakdown, are interpreted and modeled based on the changes in the kinetic energy of tumble. This enables the proposed model to secure wider applicability at various engine conditions, which were otherwise difficult to achieve. Therefore, the 0D simulation in this study was able to predict turbulent intensities at the conditions, differing in valve strategy, engine geometry, and engine operation, without changing any validation constants. Furthermore, along with the validation points used in this study, better predictions of turbulent intensity were achieved using the proposed model compared to the existing state-of-the-art model.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Intake Model With Flow Dynamics Analysismentioning

confidence: 99%