Modeling the Effects of Intake Generated Turbulence and Resolved Flow Structures on Combustion in DI Diesel Engines

Stephenson, Philip; Claybaker, Peter J.; Rutland, Christopher J.

doi:10.4271/960634

Cited by 15 publications

(6 citation statements)

References 17 publications

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“…Recently, various types of research related to piston bowl shapes have been conducted to improve fuel consumption and reduce harmful pollutants of CI engine [61][62][63][64][65][66][67][68][69][70][71][72][73]. For instance, Jaichandar et al [63] studied the performance and emissions parameters in a biodiesel fueled DI diesel engine for different combustion chambers such as Toroidal Combustion Chamber (TCC), Hemispherical Combustion Chamber (HCC) and Shallow depth Combustion Chamber (SCC).…”

Section: Combustion With Swirl Tumble and Squishmentioning

confidence: 99%

“…One of the prominent techniques to control pollutant emission is optimizing combustion with enhanced in-cylinder turbulence especially lean operating conditions. Many researchers have been investigated this technique both experimentally and numerically [18,20,25,[55][56][57][58][59][61][62][63][64]. Udayakumar et al [18] examined correlation between emission reduction and suction swirl generated inlet valve brazed with shrouds whose angles between 60˚ and 120˚ in CI engine and it was found that when the shroud angle elevated to 80˚, the CO2 emission increased with a decrease in CO and NOx emissions.…”

Section: Exhaust Emissionmentioning

confidence: 99%

“…Selamet et al [57] inquired three blockages of 20% open area produced organized intake charge motion and they showed that tumble and swirl reduced CO emissions, while increasing either NOx or HC for both operating conditions and swumble reduced NOx, HC, and CO emissions and swumble appeared to be most desirable for reduction of HC emission at partload conditions. Besides this, numerical simulation of the intake ports with different geometry was performed to study pollutant formation in DI diesel engines and it is concluded that the port configuration generating strong swirl flow resulted in enhanced soot oxidation and NOx formation [61]. Moreover, different combustion chamber geometries were considered to investigate the impact of the organized flow behavior on emissions [63][64][65][66][67].…”

Section: Exhaust Emissionmentioning

confidence: 99%

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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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Section: Combustion With Swirl Tumble and Squishmentioning

confidence: 99%

Section: Exhaust Emissionmentioning

confidence: 99%

Section: Exhaust Emissionmentioning

confidence: 99%

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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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“…Stephenson et al [21] performed a parametric study of the effect of swirl flow and pre-injection turbulence level on fuel vaporization, mixing and combustion processes by using KIVA code. They found that, in the case of constant chamber volume, the initial turbulence has a significant effect on the time to reach the 1500K and 2000K thresholds.…”

Section: Figure 3 -Emission Levels Versus Rscmentioning

confidence: 99%

Theoretical Investigation on the Influence of Physical Parameters on Soot and NOx Engine Emissions

Risi

Donateo

Laforgia

2001

Volume 2: In-Cylinder Processes: Fuel Spray, Flow, Ignition, Combustion, and Emission Formation

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CFD simulations need a certain number of parameters to calibrate both empirical and analytical models. The present investigation aims at identifying the effects of these parameters on the numerical prediction of a modified version of Kiva 3V code, which includes the use of the RNG k-ε model for turbulence, the gas/wall convective heat transfer model proposed by Han, Kelvin-Helmholtz Rayleigh-Taylor spray injection and breakup models. Ignition delay was modeled with the Shell model, whereas the laminar-turbulent characteristic time model was used for combustion. Soot formation and oxidation were calculated using Hiroyasu and Nagle and Strickland-Constable models, respectively. NOx was predicted by using the extended Zel’dovich mechanism. This study was carried out for a common-rail direct injection, small-bore Diesel engine, including the investigation of both numerical and physical parameters. Numerical parameters are intended to be variables related to breakup, turbulence, and combustion models that are adjusted according to grid resolution, engine and injection system geometry, and operating conditions. In particular, the effect of laminar and turbulent time scales, characteristic breakup length and time scales, initial turbulence kinetic energy density, initial swirl velocity profile, on engine emissions was analyzed. The investigated physical parameters were initial swirl ratio, air water content, Schmidt number for mass diffusion. All simulations were performed by changing one of the above parameters at each run and keeping approximately the same pressure and heat release rate curves. Results show that similar pressure vs. crank angle curves can be obtained with different values of these parameters but they lead to very different values of predicted emissions levels. In particular, changes of laminar and turbulent characteristic time resulted in a strong influence on NOx emissions but their effects on soot levels were minor. Mass diffusion characteristics (e.g. Schmidt number) were found to strongly affect both soot and NOx emissions. Spray parameters were found mainly to affect soot formation. Furthermore, NOx and soot emissions showed a dependence on swirl ratio and velocity profile.

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“…The turbulence generated in the wall boundary can be transported throughout the bulk of the flow by diffusion and swirl-driven secondary flow [12]. Protruding objects, such as the spark plug and valve head, have also generated turbulence due to surface shear stress and vortex shedding with global swirl motion [13]. The enhanced turbulence helps wrinkle the flame front area further, increases the burn rate, and reduces the burn duration, particularly at the early stages of combustion, resulting in better engine performance while extending the dilution limit.…”

Section: Introductionmentioning

confidence: 99%

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

He¹,

Selamet²,

Reese³

et al. 2007

SAE Technical Paper Series

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Modeling the Effects of Intake Generated Turbulence and Resolved Flow Structures on Combustion in DI Diesel Engines

Cited by 15 publications

References 17 publications

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

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

Theoretical Investigation on the Influence of Physical Parameters on Soot and NOx Engine Emissions

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

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