Effects of Port Injection Specifications on Air-Fuel Ratio and Emission Behavior under Transient Operation

Nakao, Yoshinori; Uchiyama, Yohji; Hisano, Atsushi; Saitou, Masahito; Sobakiri, Katsumi

doi:10.4271/2018-32-0012

Cited by 2 publications

(3 citation statements)

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“…Other studies also showed that the geometry influences the mean large-scale incylinder tumble motion. 2,44,45 Thus, in this research, the turbulence characteristics' shape, against the crank angle, was considered as function of the engine geometry. The non-combusting CFD analysis carried out for this study proved this assumption: 2.…”

Section: Assumptionsmentioning

confidence: 99%

“…Geometrical features are the governing characteristics of the mean large-scale in-cylinder tumble motion, as shown in the literatures. 2,44,45 Instead, engine operating conditions affect trapped in-cylinder flow state and velocity. 12,18,30,31,46 Numerical studies showed that changes in the intake flow velocity to operating conditions only affect the overall in-cylinder turbulence magnitude.…”

Section: Introductionmentioning

confidence: 99%

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A process for an efficient heat release prediction at the concepts screening stage of gasoline engine development

Rota

Morgan

Mustafa

et al. 2020

International Journal of Engine Research

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In recent years, the exploration of new combustion technologies has accelerated in response to increasingly stringent emissions regulations and fuel economy demands. Virtual engineering tools, that enable the screening of novel hardware and engine calibrations at the early stage of engine development, have become imperative to meet new emission regulations. One-dimensional engine simulations are used at the start of the design of a new engine to define the overall combustion system geometries. Later, more complex three-dimensional computational fluid dynamics calculations are coupled to one-dimensional engine system codes to optimise initial concept geometries and define a system design ready for prototyping. To provide meaningful results, one-dimensional engine system codes often use empirical-based combustion models to calculate the engine burn rate. Moreover, realistic engine burn rates responses, for the entire engine map and for different calibrations, are required to provide three-dimensional computational fluid dynamics codes with correct boundary conditions during the design optimisation phase. Thus, the burn characteristic of new non-traditional combustion solution, for which little experimental data are available, needs to be initially assumed. To improve virtual development and reduce this uncertainty, the industry’s attention shifted towards quasi-dimensional combustion models capable of providing engine burn rate predictions. Within the quasi-dimensional modelling framework, turbulence models, adding extra user-input variables, are required to capture the effect of different combustion chamber geometries on the engine combustion rate. Rigorous validation of zero-dimensional turbulence models for different engine concepts and calibrations is therefore needed to enable quasi-dimensional combustion models to predict the engine burn rate. An alternative methodology, with limited dependency on previous test data, is required to enhance the exploration of novel combustion strategies and geometric architectures. An available process, based on a quasi-dimensional combustion stochastic reactor model, a one-dimensional engine system model and non-combusting three-dimensional computational fluid dynamics calculations, was used for this work. The approach uses limited non-combusting computational fluid dynamics calculations and a previously developed scaling factor response for the stochastic reactor model turbulence input ( τSRM) to quickly predict the engine rate of heat release. In this work, the scaling factor response was assessed against two different engine variants over a variety of engine operating conditions. Moreover, the same response was used to predict the effect of different bore-to-stroke ratios on the engine combustion rate and knock tolerance. Non-combusting computational fluid dynamics and one-dimensional engine system simulations have been carried out to investigate changes in turbulence characteristics due to different engine variants and bore-to-stroke ratios. It was shown that limited number of non-combusting computational fluid dynamics runs is required to characterise the in-cylinder turbulence for each explored engine variant. The scaling factor response was used to manipulate the turbulence input ( τSRM) resulting in good engine burn rates predictions for the explored engine variants and bore-to-stroke ratios. The presented methodology showed augmented predictive capabilities and has potential to move the engine development towards a less hardware dependent virtual approach, offering a practical solution for the exploration of new engine concepts.

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Section: Assumptionsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

A process for an efficient heat release prediction at the concepts screening stage of gasoline engine development

Rota

Morgan

Mustafa

et al. 2020

International Journal of Engine Research

View full text Add to dashboard Cite

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“…The fuel is directed to the hot surface of the intake valve so it evaporates. The injection pressure, injection time, injection angle and the number of injections in one cycle affect mixture formation [1][2][3][4][5][6][7].…”

Section: Introductionmentioning

confidence: 99%

The Effect of Injection Parameters on Fuel Consumption and Emissions in A PFI Small Spark Ignition Engine

Demirci

Doğan

Cihan

et al. 2021

International Journal of Automotive Science and Technology

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Mixture formation in port fuel spark ignition engines is one of the most im-portant parameters, which affect combustion and emissions. In this study, the ef-fects of different injection start timings and some other port fuel injection (PFI) parameters on the performance and emissions of a water cooled and single cylin-der spark ignition engine were examined experimentally. The experiments were performed at different engine speeds (1200 and 1500 rpm for effect of injection pressure and 1500 rpm for changing injection timings) and different engine loads (3 bar and 5 bar for injection pressure and 1 bar and 5 bar for start of injection). The start of injection was chosen according to intake pressure measurements. The experiment results showed that brake specific fuel consumption (BSFC) and total hydrocarbon (THC) emissions are increased by the increase of the injection pressure. Because with the increase of injection pressure, the fuel can reach the intake manifold wall or intake valve. Therefore, the fuel enters the cylinder as a droplet. Different start of injection experiments showed that injection times have an effect on emissions and performance. The minimum brake specific fuel con-sumption and THC values were obtained at -243 °CA value of injection start. The twice injection in one cycle increased brake specific fuel consumption and THC emissions.

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Effects of Port Injection Specifications on Air-Fuel Ratio and Emission Behavior under Transient Operation

Cited by 2 publications

References 1 publication

A process for an efficient heat release prediction at the concepts screening stage of gasoline engine development

A process for an efficient heat release prediction at the concepts screening stage of gasoline engine development

The Effect of Injection Parameters on Fuel Consumption and Emissions in A PFI Small Spark Ignition Engine

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