Effect of Intake Primary Runner Blockages on Combustion Characteristics and Emissions with Stoichiometric and EGR-diluted Mixtures in SI Engines

He, Yufei; Selamet, Ahmet; Reese, Ronald; Vick, R. K.; Amer, Amer

doi:10.4271/2007-01-3992

Cited by 8 publications

(4 citation statements)

References 26 publications

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“…Looking at the velocity analysis, it can be said that the high flow velocity seen in NCCS developed as a result of the combination of squish and swirl flows. Increasing the flame area increases the heat transfer level of the unburned gas [26]. Due to the increased heat transfer, the increase in the temperature of the unburned gas causes the combustion to take place faster, and more fuel to participate in the combustion event.…”

Section: Resultsmentioning

confidence: 99%

Numerical investigation of different combustion chamber on flow, combustion characteristics and exhaust emissions

Temizer

Cihan

ÖNCÜOĞLU

2023

European Mechanical Science

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This study includes numerical analysis of diesel engine with different bowl geometry. 3D CFD analyzes of the engine with asymmetrical piston geometry were performed in Ansys Forte software. In the study, a single-cylinder, four-stroke and direct injection diesel engine was used. It has been tested where the maximum torque is obtained as the operating condition at 2000 rpm. According to the results obtained from the analyzes, the new combustion chamber system (NCCS) geometry provided a 40.3% reduction in soot emissions while NO emissions increased slightly with the 8-cavity bowl geometry created in the combustion chamber compared to the standard combustion chamber system (SCCS). Increasing air velocity and turbulent kinetic energy (TKE) values in the combustion chamber affected the evaporation levels of the fuels. As a result, the improved mixture formation caused a decrease in incomplete combustion products (CO, HC and soot). The NCCS geometry according to SCCS type, an increase of approximately 4.2% occurred in the calculated squish rates. It has been observed that the increase in the bowl surface area causes the combustion and thus the temperature to spread over a larger area on the piston.

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Section: Resultsmentioning

confidence: 99%

Numerical investigation of different combustion chamber on flow, combustion characteristics and exhaust emissions

Temizer

Cihan

ÖNCÜOĞLU

2023

European Mechanical Science

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“…Moreover, volumetric efficiency is not necessarily reduced. In this sense, adjustable deflectors are an interesting option for enhancing and controlling the charge motion and turbulence at low load [21,30,31].…”

Section: Geometric Modifications: Flow Deflectorsmentioning

confidence: 99%

In-cylinder flow control in a four-valve spark ignition engine: numerical and experimental steady rig tests

Ramajo

Zanotti

Nigro

2011

Proceedings of the Institution of Mechanical Engineers, Part D:

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Computational fluid dynamic (CFD) simulations and experimental steady flow tests (flow discharge, swirl, and tumble) were carried out to study the in-cylinder flow in a commercial four-valve spark ignition engine. The present investigation was aimed at analysing and controlling the generation of macro-vortex structures (swirl and tumble) during the inlet process. A comparative study of the most commonly employed tumble benches along with in-house design was performed, the last showing some advantages with respect to the others. The outcomes from the simulations were in agreement with experimental results. Mainly, the tumble generation rate was in general proportional to the valve lift. However, tumble was reduced drastically at medium valve lift due to a change in the vortex pattern. A stagnation zone was observed between inlet valves. CFD calculations successfully captured this tumble-fall effect, which was related to characteristic changes in the vortex pattern downstream of the inlet valves at medium valve lift. This affects tumble production without affecting the mass flowrate efficiency. Finally, at high valve lifts the tumble production and the vortex pattern were recovered. The capability of the cylinder head to induce swirl, tumble, or combined swirl-tumble by modifying the valve timing or by introducing adjustable flow deflectors was evaluated using CFD. Several valve timing strategies were analysed: some of them produced significant swirl, but introduced high mass flowrate losses. On the other hand, adjustable flow deflectors were shown to be an interesting alternative to induce swirltumble at low load and to improve tumble at high load.

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“…The increased flame front area raises heat transfer to nearby unburned gas. Since the temperature of the unburned gas elevates more quickly due to the increased heat transfer, it can reach ignition temperature and initiate combustion much faster than without a wrinkled flame front [51]. Hence, turbulence before ignition increases burn rate and reduce combustion duration.…”

Section: Combustion With Swirl Tumble and Squishmentioning

confidence: 99%

Influence of swirl, tumble and squish flows on combustion characteristics and emissions in internal combustion engine-review

Kaplan

2019

International Journal of Automotive Engineering and Technologies

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This study gives an overview of available literature on flow patterns such as swirl, tumble and squish in internal combustion engines and their impacts of turbulence enhancement, combustion efficiency and emission reduction. Characteristics of in-cylinder flows are summarized. Different design approaches to generate these flows such as directed ports, helical ports, valve shrouding and masking, modifying piston surface, flow blockages and vanes are described. How turbulence produced by swirl, tumble and squish flows are discussed. Effects of the organized flows on combustion parameters and exhaust emission are outlined. This review reveals that the recent investigations on the swirl, tumble and squish flows are generally related to improving in-cylinder turbulence. Thus, more experimental and numerical studies including the impacts of this organized flows on turbulence production, combustion behavior and pollutant formation inside the cylinder are needed.

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Effect of Intake Primary Runner Blockages on Combustion Characteristics and Emissions with Stoichiometric and EGR-diluted Mixtures in SI Engines

Abstract: In-cylinder pressure [bar] Volume/Volume at BDC In-cylinder pressure [bar] Volume/Volume at BDC In-cylinder pressure [bar] Volume/Volume at BDC In-cylinder pressure [bar] Volume/Volume at BDC In-cylinder pressure [bar] Volume/Volume at BDC In-cylinder pressure [bar] Volume/Volume at BDC

Cited by 8 publications

References 26 publications

Numerical investigation of different combustion chamber on flow, combustion characteristics and exhaust emissions

Numerical investigation of different combustion chamber on flow, combustion characteristics and exhaust emissions

In-cylinder flow control in a four-valve spark ignition engine: numerical and experimental steady rig tests

Influence of swirl, tumble and squish flows on combustion characteristics and emissions in internal combustion engine-review

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