Investigation of the Swirl Effect on Diffusion Flame in a Direct-Injection (DI) Diesel Engine Using Image Processing Technology

Kim, Ki-Bum; Chung, Jaewoo; Lee, Kihyung; Lee, Kwan-Soo

doi:10.1021/ef8003224

Cited by 22 publications

(10 citation statements)

References 13 publications

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“…Increasing number of pilots makes mixing less sensitive to swirl ratio. This is in agreement with what reported by Kibum [22] when analysing flame visualizations in a single-cylinder optical diesel engine; when the injection timing was set at 26°BTDC, the fuel was found to be sufficiently mixed with air before the ignition started, regardless of whether there was swirl or not. This was in good agreement also with a previous computational study that indicated that the early injection timings promoted premixture formation [23].…”

Section: Figures 4 and 5 Provide Detailed Fuel Distribution Informatisupporting

confidence: 91%

CFD Investigation on the Influence of In-Cylinder Mixture Distribution from Multiple Pilot Injections on Cold Idle Behaviour of a Light Duty Diesel Engine

Rocca

MacMillan

Shayler

et al. 2014

SAE Technical Paper Series

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Cold idle operation of a modern design light duty diesel engine and the effect of multiple pilot injections on stability were investigated. The investigation was initially carried out experimentally at 1000rpm and at −20°C. Benefits of mixture preparation were initially explored by a heat release analysis. Kiva 3v was then used to model the effect of multiple pilots on in-cylinder mixture distribution. A 60° sector of mesh was used taking advantage of rotational symmetry. The combustion system and injector arrangements mimic the HPCR diesel engine used in the experimental investigation. The CFD analysis covers evolutions from intake valve closing to start of combustion. The number of injections was varied from 1 to 4, but the total fuel injected was kept constant at 17mm 3 /stroke. Start of main injection timing was fixed at 7.5°BTDC. The experimental study shows that increasing the number of pilots improves stability and leads to fuel preparation resulting in higher initial peak rate of heat release. CFD results show that multiple pilot injections are capable of better fuel distribution; noticeable by injecting just one pilot compared to no pilot. A further pilot increases the surface area of the vapour cloud to a greater extent. Three pilots allow for fuel to be well distributed in the full bowl with no lean regions; a greater proportion of the fuel is exposed to the glow plug temperature. The glow plug is enclosed by a fuel cloud over a longer period of time as the number of pilot injections is increased.

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Section: Figures 4 and 5 Provide Detailed Fuel Distribution Informatisupporting

confidence: 91%

CFD Investigation on the Influence of In-Cylinder Mixture Distribution from Multiple Pilot Injections on Cold Idle Behaviour of a Light Duty Diesel Engine

Rocca

MacMillan

Shayler

et al. 2014

SAE Technical Paper Series

View full text Add to dashboard Cite

show abstract

“…Therefore, this resulted in biodiesel fuel to have a small surface area of the fuel and air which may lead to less mixing, diffusion and evaporation. It is believed that the occurrence of small surface of fuel injection is related to the low value of TKE [34,41]. Kim et al [41] investigated in-cylinder TKE by using swirl control valves and reported that in-cylinder TKE increases will reduce fuel penetration length and the impingement of the fuel against piston head.…”

Section: Penetration Length and Cone Anglementioning

confidence: 99%

“…It is believed that the occurrence of small surface of fuel injection is related to the low value of TKE [34,41]. Kim et al [41] investigated in-cylinder TKE by using swirl control valves and reported that in-cylinder TKE increases will reduce fuel penetration length and the impingement of the fuel against piston head. To confirm their results, they used flame visualization and analyses of images.…”

Section: Penetration Length and Cone Anglementioning

confidence: 99%

Simulation of Improvements to In-cylinder Mixing of Biodiesel with Air by Incorporating Guide Vanes into the Air Intake System

Bari

Johansen

Alherz

2015

Procedia Engineering

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Engine manufacturers and consumers around the world are concerned for the fuel efficiency and ecological footprint of their engines, and this concern has motivated increased production and usage of alternative fuels. Biodiesel is renewable and behaves similarly to diesel in an engine. Further, the emission of carbon dioxide from burning biodiesel in engines is offset by the consumption of carbon dioxide by the plant producing biodiesel feed stock. Biodiesel does, however, have an undesirable higher viscosity, larger and heavier molecules which lead to slower atomisation and less mixing with air, resulting lower combustion efficiency. To mitigate these problems, this paper proposes a guide vane swirl and tumble device (GVSTD) to be installed within the intake port for the purpose of increasing the turbulence of the air flow into the cylinder and to aid the atomisation and mixing of the biodiesel molecules with air.

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“…Higher in-cylinder TKE would effectively break up larger fuel droplets and mix with air to provide improved combustion with less carbon deposits inside the cylinder (Bari & Saad, 2013). K. Kim, Chung, Lee, and Lee (2008) found that the swirl control valve can effectively increase the in-cylinder TKE by using flame visualization and analyses of images. Figure 13 shows a comparison of the TKE for various piston shapes when the CMCV is open and closed.…”

Section: Effect Of the Piston Shape On The Tumble And Tke Valuesmentioning

confidence: 99%

Effect of the piston top contour on the tumble flow and combustion features of a GDI engine with a CMCV: a CFD study

Yin

Zhang

Sun

et al. 2016

Engineering Applications of Computational Fluid Mechanics

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In spite of much progress in the development of gasoline direct injection (GDI) engines, choosing an appropriate piston top contour to obtain desirable combustion efficiency is still an arduous process for engineers. This study investigates the combined effects of piston bowl geometry and a charge motion control valve (CMCV) on tumble flow and combustion features in GDI engines. Based on the model validation, the processes of intake, spray, mixture formation and combustion at different engine speeds are simulated and analyzed for different piston shapes for the two cases of opening and closing the CMCV. The results show that the bowl on the top of piston is beneficial for the formation and development of tumble flow. The flat top piston with the CMCV closed is able to achieve acceptable combustion pressure. However, with the increase of engine speed and load, the advantages of the flat top pistons gradually disappear; the dual offset bowl piston has a minimum tumble ratio and turbulence kinetic energy (TKE) at the end of the compression stroke because of the projection in the middle of the piston top surface which leads to a lower pressure rise rate and a reduced flame propagation speed at high load. The closed CMCV contributes to a faster evaporation rate and a more uniform mixture at lower speeds. It is not recommended for use at high speeds due to lower intake air mass and reduced combustion pressure. The research provides an effective way for engineers to choose an appropriate piston top contour combined with a CMCV to obtain desirable combustion efficiency. ARTICLE HISTORY

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Investigation of the Swirl Effect on Diffusion Flame in a Direct-Injection (DI) Diesel Engine Using Image Processing Technology

Cited by 22 publications

References 13 publications

CFD Investigation on the Influence of In-Cylinder Mixture Distribution from Multiple Pilot Injections on Cold Idle Behaviour of a Light Duty Diesel Engine

CFD Investigation on the Influence of In-Cylinder Mixture Distribution from Multiple Pilot Injections on Cold Idle Behaviour of a Light Duty Diesel Engine

Simulation of Improvements to In-cylinder Mixing of Biodiesel with Air by Incorporating Guide Vanes into the Air Intake System

Effect of the piston top contour on the tumble flow and combustion features of a GDI engine with a CMCV: a CFD study

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