Numerical Analysis of In-cylinder Tumble Flow Structures – Parametric 0D Model Development

Falfari, Stefania; Brusiani, Federico; Bianchi, Gian Marco

doi:10.1016/j.egypro.2014.01.104

Cited by 12 publications

(3 citation statements)

References 11 publications

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“…In [2] the authors presented a theoretical model capable of describing the interaction between the squish velocity and the tumble velocity depending on the engine class.…”

Section: Literature Summary On the Tumble Motionmentioning

confidence: 99%

“…As in the papers [1,2], the present paper deals with PFI motorcycle engines characterized by having high stroke-to-bore ratio (C/D) and small bore (D), as summarized in Table 1. In [1] simulations on three different engine industrial configurations (Table 2) were ran by means a 3D CFD code: the simulation results showed that the configuration having the highest percentage squish area and the intake duct most capable of generating high tumble ratio at IVC (namely C3_original) was characterized by the lowest combustion velocity.…”

Section: Present Paper Target and Originalitymentioning

confidence: 99%

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3D CFD Analysis of the Influence of Some Geometrical Engine Parameters on Small PFI Engine Performances - The Effects on Tumble Motion and Mean Turbulent Intensity Distribution

Falfari¹,

Bianchi²,

Nuti³

2012

SAE Technical Paper Series

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In scooter/motorbike engines coherent and stable tumble motion generation is still considered an effective mean in order to both reduce engine emissions and promote higher levels of combustion efficiency. The promotion of a stable and coherent tumble structure is largely believed in literature to enhance in-cylinder turbulence accelerating combustion process. In small PFI engine layout and weight constraints limit the adoption of more advanced concepts. In previous technical papers the authors demonstrated the influence of head shape and squish area on tumble vortex formation, development, breakdown and on final value of turbulence close to spark plug for small PFI engines. The main result of the this research was that the combustion chamber having the less squish area resulted to have the highest level of turbulence close to spark plug at ignition time. The geometry under analysis in the current paper is a 3-valves pent-roof motorcycle engine. 3D CFD simulations were ran at 6500 rpm with AVL FIRE code. The chosen engine geometry was the geometry found to be the best setup in terms of turbulence and combustion performances in the previous paper. In the present paper the head shape and the squish area were kept constant and the following engine parameters were varied: the intake duct angle (the angle of the intake duct entering the head was reduced of 6%, i.e. it was more directed toward the exhaust side of the chamber), the piston shape, and finally the compression ratio (it was reduced of 9%). The main goal of the current analysis is to understand which of these parameters is predominant in accelerating combustion for directing engine design toward the best setup .

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“…In [2] the authors presented a theoretical model capable of describing the interaction between the squish velocity and the tumble velocity depending on the engine class.…”

Section: Literature Summary On the Tumble Motionmentioning

confidence: 99%

Section: Present Paper Target and Originalitymentioning

confidence: 99%

3D CFD Analysis of the Influence of Some Geometrical Engine Parameters on Small PFI Engine Performances - The Effects on Tumble Motion and Mean Turbulent Intensity Distribution

Falfari¹,

Bianchi²,

Nuti³

2012

SAE Technical Paper Series

Self Cite

View full text Add to dashboard Cite

show abstract

“…In [24] the authors used numerical simulation to assess the influence of some intake duct geometrical parameters on the tumble motion generation during both the intake and the compression strokes to highlight the turbulence production process. In [25] the authors presented a theoretical model capable of describing the interaction between the squish velocity and the tumble velocity depending on the engine class. Ramajo et al [26] reported results obtained running a mono-dimensional (1D) model developed for predicting in-cylinder tumble motion formation and breakdown till the appearance of high turbulence level close to TDC.…”

Section: Introductionmentioning

confidence: 99%

Effects of Scavenging System Configuration on In-Cylinder Air Flow Organization of an Opposed-Piston Two-Stroke Engine

Zhao

Zhang

et al. 2015

Energies

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Abstract:In-cylinder air flow is very important from the point of view of mixture formation and combustion. In this direction, intake chamber structure and piston crown shape play a very crucial role for in-cylinder air pattern of opposed-piston two-stroke (OP2S) engines. This study is concerned with the three-dimensional (3D) computational fluid dynamics (CFD) analysis of in-cylinder air motion coupled with the comparison of predicted results with the zero-dimensional (0D) parametric model. Three configurations viz., a flat piston uniform scavenging chamber, a flat piston non-uniform scavenging chamber and a pit piston non-uniform scavenging chamber have been studied. 0D model analysis of in-cylinder air flow is consistent with 3D CFD simulation. It is concluded that a pit piston non-uniform scavenging chamber is the best design from the point of view of tumble ratio, turbulent kinetic energy and turbulent intensity, which play very important roles in imparting proper air motion. Meanwhile a flat piston uniform scavenging chamber can organize a higher swirl ratio and lower tumble ratio which is important to improve the scavenging process.

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Numerical Investigation of Swirl and Tumble Motion in the Cylinder and Their Effect on Combustion of Gasoline–Methanol Blends in SI Engine

Yadav

Maurya

2021

Lecture Notes in Mechanical Engineering

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Numerical Analysis of In-cylinder Tumble Flow Structures – Parametric 0D Model Development

Cited by 12 publications

References 11 publications

3D CFD Analysis of the Influence of Some Geometrical Engine Parameters on Small PFI Engine Performances - The Effects on Tumble Motion and Mean Turbulent Intensity Distribution

3D CFD Analysis of the Influence of Some Geometrical Engine Parameters on Small PFI Engine Performances - The Effects on Tumble Motion and Mean Turbulent Intensity Distribution

Effects of Scavenging System Configuration on In-Cylinder Air Flow Organization of an Opposed-Piston Two-Stroke Engine

Numerical Investigation of Swirl and Tumble Motion in the Cylinder and Their Effect on Combustion of Gasoline–Methanol Blends in SI Engine

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