Stratified Mixture Research Articles

Evaluation of injection and ignition schemes for the ultra-lean combustion direct-injection LPG engine to control particulate emissions

The high level of particulate emission in ultra-lean combustion direct injection engine was obstacles for real application and satisfying the further upcoming regulation. The use of LPG (liquefied petroleum gas) in lean direct injection engines has the potential to reduce carbon-related emissions owing to its simple structure, and it can become an easily stratified mixture because of its higher vapor pressure. In this respect, the effects of the injection and ignition schemes on combustion and emission characteristics, including particle emission of ultra-lean combustion through LPG, were investigated. Four different injections schemes in order for forming stratified mixture and two ignition schemes (single charge ignition and multi-charge ignition) were employed to achieve simultaneous harmful emissions and fuel consumption reduction.The experimental results reveal that the fully stratified injection strategies indicate an improvement of approximately 18% in thermal efficiency, but combustion fluctuation was observed owing to stratification. Moreover, simultaneous reductions in the NOX (Nitric Oxides) and CO (Carbon monoxide) emissions were observed (when compared to homogeneous stoichiometric combustion) while increasing the particulate matter emission. In order to stabilize the combustion and reduce the level of soot, a multi-charge ignition was introduced to the selected injection strategies (LBM1 and LBM2). Multi-charge ignition successfully reduces particulate mass by about 10% and secures the combustion stability slightly; however, it increases the particle number concentration.

Impact of injection settings operating with the gasoline Partially Premixed Combustion concept in a 2-stroke HSDI compression ignition engine

Partially Premixed Combustion (PPC) using gasoline-like fuels has proven its potential to control or even break the NOx and soot emissions trade-off, retaining the high efficiency levels characteristic of the conventional diesel combustion (CDC) concept. However, selecting an appropriate fuel and a suitable injection strategy is essential to assure a successful PPC operation in the full engine map. Additionally, extending the limit of PPC beyond 10bar IMEP was not possible due to excessively high pressure gradients and onset of knocking-like combustion, so the CDC concept has to be adopted and the conventional trade-off between NOx and soot emissions was recovered. Present investigation focuses on evaluating the use of a multiple injection strategy for extending the load range of the PPC concept to medium/high load conditions, when using a commercial RON95 gasoline in a 2-stroke engine under development. Experimental results confirm how with a fine tuned triple injection strategy it is possible to reach extremely low NOx and soot levels keeping combustion efficiency over 96%, while indicated efficiency is improved compared to a well-optimized point obtained operating with the CDC concept. Finally, the research work is completed by including 3D-CFD modeling activities that are carried out to contribute to the understanding on how the mixture preparation and stratification prior to the start of combustion impacts its development and particularly the experimentally observed pollutant emissions trends.

Development of a reduced chemical mechanism targeted for a 5-component gasoline surrogate: A case study on the heat release nature in a GCI engine

Gasoline Compression Ignition (GCI) is a promising engine operating mode that can reduce maximum pressure rise rate (MPRR) without knock tendency and better control the combustion phasing compared to the Homogeneous Charge Compression Ignition (HCCI) by using a late direct-injection (DI). In this study, a 107-species reduced mechanism and a 207-species skeletal mechanism were developed using the Computer Assisted Reduction Mechanism (CARM) and validated under engine conditions for a newly developed 5-component surrogate for a Haltermann 437 certification gasoline (AKI=93). Then, 3D computational fluid dynamics (CFD) simulations with an optimized grid size determined by a grid convergence study were performed with the 107-species reduced mechanism and the 5-component certification gasoline surrogate. Two experimental boosted GCI cases with similar, moderate MPRR and heat release parameters, but different second DI timings (−52° aTDC and −5° aTDC), were validated and analyzed. For the −52° aTDC DI case, the combustion can be interpreted as a partially sequential auto-ignition due to the competition between the charge cooling effect and the equivalence ratio (ϕ)-sensitive effect of the stratified mixture, which is responsible for mitigating the MPRR. For the −5° aTDC DI case, the combustion can be decoupled into a partially sequential auto-ignition and a subsequent non-premixed combustion by the DI fuel near top dead center in the compression stroke. The MPRR is relaxed through the slow, mixing-limited combustion between the injected fuel and the premixed mixture.

Long-term structural and biomass dynamics of virgin Tsuga canadensis-Pinus strobus forests after hurricane disturbance.

The development of old-growth forests in northeastern North America has largely been within the context of gap-scale disturbances given the rarity of stand-replacing disturbances. Using the 10-ha old-growth Harvard Tract and its associated 90-year history of measurements, including detailed surveys in 1989 and 2009, we document the long-term structural and biomass development of an old-growth Tsuga canadensis-Pinus strobus forest in southern New Hampshire, USA following a stand-replacing hurricane in 1938. Measurements of aboveground biomass pools were integrated with data from second- and old-growth T.canadensis forests to evaluate long-term patterns in biomass development following this disturbance. Ecosystem structure across the Tract prior to the hurricane exhibited a high degree of spatial heterogeneity with the greatest levels of live tree basal area (70-129m2 /ha) on upper west-facing slopes where P.strobus was dominant and intermixed with T.canadensis. Live-tree biomass estimates for these stratified mixtures ranged from 159 to 503Mg/ha at the localized, plot scale (100m2 ) and averaged 367Mg/ha across these portions of the landscape approaching the upper bounds for eastern forests. Live-tree biomass 71years after the hurricane is more uniform and lower in magnitude, with T.canadensis currently the dominant overstory tree species throughout much of the landscape. Despite only one living P.strobus stem in the 2009 plots (and fewer than five stems known across the entire 10-ha area), the detrital legacy of this species is pronounced with localized accumulations of coarse woody debris exceeding 237.7-404.2m3 /ha where this species once dominated the canopy. These patterns underscore the great sizes P.strobus attained in pre-European landscapes and its great decay resistance relative to its forest associates. Total aboveground biomass pools in this 71-year-old forest (255Mg/ha) are comparable to those in modern old-growth ecosystems in the region that also lack abundant white pine. Results highlight the importance of disturbance legacies in affecting forest structural conditions over extended periods following stand-replacing events and underscore that post-disturbance salvage logging can alter ecosystem development for decades. Moreover, the dominant role of old-growth P.strobus in live and detrital biomass pools before and after the hurricane, respectively, demonstrate the disproportionate influence this species likely had on carbon storage at localized scales prior to the widespread, selective harvesting of large P.strobus across the region in the 18th and 19th centuries.

Turbulent spark-jet ignition in SI gas fuelled engine

The article contains a thermodynamic analysis of a new combustion system that allows the combustion of stratified gas mixtures with mean air excess coefficient in the range 1.4-1.8. Spark ignition was used in the pre-chamber that has been mounted in the engine cylinder head and contained a rich mixture out of which a turbulent flow of ignited mixture is ejected. It allows spark-jet ignition and the turbulent combustion of the lean mixture in the main combustion chamber. This resulted in a two-stage combustion system for lean mixtures. The experimental study has been conducted using a single-cylinder test engine with a geometric compression ratio e = 15.5 adapted for natural gas supply. The tests were performed at engine speed n = 2000 rpm under stationary engine load when the engine operating parameters and toxic compounds emissions have been recorded. Analysis of the results allowed to conclude that the evaluated combustion system offers large flexibility in the initiation of charge ignition through an appropriate control of the fuel quantities supplied into the pre-chamber and into the main combustion chamber. The research concluded with determining the charge ignition criterion for a suitably divided total fuel dose fed to the cylinder.

Laminar flame speeds of stratified methane, propane, and n-heptane flames

A numerical study on stratified flames of three hydrocarbon fuels, i.e., methane, propane and n-heptane, is conducted using a unsteady, compressible and reacting flow solver ASURF-Parallel. For each fuel, both fuel consumption speeds and flame front propagation speeds of a rich-to-lean stratified flame are compared to those of their corresponding homogeneous flames. For fuel consumption speeds, the methane/air stratified flame is overall faster than those of homogeneous flames due to chemical activities enhanced by key radicals and species from rich burnt gas mixtures. In contrast, stratified flames of both propane/air and n-heptane/air mixtures have lower fuel consumption speeds compared to their homogeneous flames on the rich side, due to reduced level of key radicals consumed by intermediate hydrocarbon species from rich burnt gases. For flame front propagation speeds, stratified flames of all three fuels are found faster than their corresponding homogeneous flames, due to consistently enhanced total heat release rate. Stronger enhancement of laminar flame speeds of stratified mixtures is observed in methane/air mixtures, compared to propane and n-heptane. Burnt gas of rich methane/air mixtures consists of relatively more molecular hydrogen, which assists fuel consumption and heat release at flame front. Moreover, molecular hydrogen has a stronger impact on laminar flame speeds of methane/air mixtures thus an even stronger enhancement on laminar flame speeds of methane/air stratified mixtures is observed. H/C ratio along with local equivalence ratio at flame front are proposed to provide a unique identification of the exact mixture composition of stratified flames.

Combustion and Emission Characteristics According to the Fuel Injection Ratio of an Ultra-Lean LPG Direct Injection Engine

The effect of the fuel injection ratio on the combustion and emission characteristics of stratified lean mixture combustion was investigated for a spray-guided liquefied petroleum gas (LPG) direct injection engine. Inter-injection spark-ignition combustion—a specially designed combustion strategy for LPG fuel derived from a two-staged injection—was employed to maximize the improvement in thermal efficiency when combustion stability is secured. When changing the fuel injection ratio, the optimum spark advance and fuel injection timings were experimentally determined to maximize the thermal efficiency based on sweeping timings. The optimum fuel injection ratio with the highest thermal efficiency (42.76%) and stable operation was 60%/40%, with the optimization of the spark advance and fuel injection timing, because of the locally rich mixture region in the recirculation zone. NOx emissions were at their highest level with a fuel injection ratio of 60%/40% because of the high combustion temperature, and the levels of total hydrocarbon and CO emissions with 50%/50% and 60%/40% fuel injection ratios were similar, whereas emissions at 70%/30% were significantly higher because of fuel wetting and the formation of over-lean mixture.

Effects of engine operating conditions on particle emissions of lean-burn gasoline direct-injection engine

Direct injection of fuel into the cylinder of an engine leads to the problem of particulate matter (PM) emissions. Lean-burn gasoline direct-injection (GDI) engines are known to emit higher levels of ultrafine particles than do conventional engines. The level of PM emissions by lean-burn GDI engines is unlikely to meet the EURO-VI emissions standards. In this study, the effects of combustion strategy and excess air ratio on the PM concentrations and particle size distribution were evaluated for a naturally aspirated lean-burn GDI engine. The engine operating conditions—including the fuel-air mixture and load—were varied in order to analyze the PM formation and the particle size distribution. The PM concentration was found to increase dramatically at an excess air ratio of 1.5, at which ratio lean combustion with a stratified mixture occurred. This was regarded as being the transition region between the premixed flames and the stratified mixture flames. Further, an increase in the excess air ratio to beyond 2.0 caused the PM concentration and particle number to increase again, possibly as a result of the relatively high ambient pressure and lower combustion temperature.

Effects of Mixture Distribution on Localized Forced Ignition of Stratified Mixtures: A Direct Numerical Simulation Study

ABSTRACTThe influences of initial mixture distribution on localized forced ignition of globally stoichiometric stratified mixtures have been analyzed using three-dimensional compressible direct numerical simulations. The globally stoichiometric mixtures (i.e., ) for different root-mean-square (rms) values of equivalence ratio (i.e., = 0.2, 0.4, and 0.6) and the Taylor micro-scale of equivalence ratio variation (i.e., 2.1, 5.5, and 8.3 with being the Zel’dovich flame thickness of stoichiometric mixture) have been analyzed for different initial rms values of turbulent velocity . The equivalence ratio variation is initialized following both Gaussian and bi-modal distributions for a given set of values of and in order to analyze the effects of mixture distribution. The localized forced ignition is accounted for by considering a source term in the energy conservation equation that deposits energy for a stipulated time interval. It has been demonstrated that the initial equivalence ratio distribution has significant effects on the extent of burning of stratified mixtures following successful localized forced ignition. It has been found that an increase in ) has adverse effects on the burned gas mass, whereas the effects of on the extent of burning are non-monotonic and dependent on for initial bi-modal mixture distribution. The initial Gaussian mixture distribution exhibits an increase in burned gas mass with decreasing , but these cases are more prone to flame extinction for high values of than the corresponding bi-modal distribution cases. Detailed physical explanations have been provided for the observed mixture distribution, , , and dependences on the extent of burning following localized forced ignition of stratified mixtures.

Statistical behavior of fuel mass fraction variance transport in turbulent flame–droplet interaction: A direct numerical simulation analysis

ABSTRACTThree-dimensional direct numerical simulations (DNS) data of statistically planar turbulent spray flames propagating into monodisperse droplets for different values of droplet diameter ad and droplet equivalence ratio ϕd have been used to analyze the statistical behavior of the fuel mass fraction variance and its transport in the context of Reynolds-averaged Navier–Stokes (RANS) simulations. The algebraic closure, which was previously derived for high Damköhler number turbulent stratified mixture combustion, has been shown not to capture statistical behavior of for turbulent spray flames, because the underlying assumptions behind the original modeling are invalid for the cases considered in this analysis. The modeling of the unclosed terms of the variance transport equation (i.e., the turbulent transport term T1, the reaction rate contribution T3, the evaporation contribution T4, and the dissipation rate term –D2) has been analyzed in the context of RANS simulations. The models previously proposed in the context of turbulent gaseous stratified flames have been considered here to assess their suitability for turbulent spray flames. Model expressions have been identified for and −D2 which have been shown to perform satisfactorily in all cases considered in the current study. However, the model previously proposed for T3 in the context of turbulent gaseous stratified flames has been found to be inadequate for turbulent spray flames and further consideration of the modeling of this unclosed term is therefore necessary.

Combustion characteristics of gasoline and n-butane under lean stratified mixture conditions in a spray-guided direct injection spark ignition engine

In the present research, macroscopic spray visualization tests were carried out in a constant-volume combustion chamber (CVCC) under replicated ambient conditions of a stratified combustion mode, in order to achieve stable stratified combustion with gasoline and n-butane. With the spray visualization tests, n-butane spray was immediately evaporated after the end of injection, unlike gasoline. Compared to gasoline, the spray structure of n-butane was collapsed toward the injector tip axis, and the collapse became severe as injection pressure was increased. Based on those results, a single-cylinder metal engine experiment was conducted to investigate combustion and emission characteristics of gasoline and n-butane. Due to the different spray characteristics between gasoline and n-butane, operational parameters including injection pressure and injection as well as ignition timings were set to be different for each fuel, for stable stratified combustion. n-Butane required shorter mixture formation time, but the range of suitable mixture formation times was narrower than that of gasoline. However, the combustion efficiency of n-butane was higher than that of gasoline under stable stratified combustion conditions. In addition, unlike gasoline, n-butane showed a similar heat release rate (HRR) trend regardless of injection and ignition timings. Particulate matter emission of n-butane was nearly zero while nitrogen oxides (NOx) emissions were similar to those of gasoline when the combustion phase of each fuel was similar.

Exploring the performance limits of a stratified torch ignition engine using numerical simulation and detailed experimental approaches

In a torch ignition engine system, the combustion starts in a pre-combustion chamber, where the pressure increase pushes the combustion jet flames through calibrated nozzles to be precisely targeted into the main combustion chamber. This paper presents the layout of the prototype engine and the developed fuel injection system. It continues with a detailed description of the performance of the torch ignition engine running on a gasoline/ethanol blend for different mixture stratification levels as well as engine speeds and loads. Also detailed analyses of specific fuel consumption, thermal and combustion efficiency, specific emissions of CO2 and the main combustion parameters are carried out. A numerical model based on thermodynamic and kinetic analyses has been established in order to explore the performance limit of a stratified torch ignition engine. The paper concludes presenting the main numerical results obtained in this work, which show a significant increase in the torch ignition engine performance as compared with the commercial baseline engine.

Effect of hydrogen proportion on lean burn performance of a dual fuel SI engine using hydrogen direct-injection

Hydrogen is a fuel that has low ignition energy, wide inflammability limit and superb combustion rate, using hydrogen-enriched gasoline mixture in SI engine is a favorable way to improve the performance of burning process, particularly in lean-burn condition. Hydrogen direct injection allows forming stratified mixture with back fire prevention and independent with intake air content. An experimental investigation was performed to analyze the stratified lean-burn characteristics of a hydrogen-enhanced gasoline engine with hydrogen direct injection. Five different hydrogen additional fractions (3.9%, 5.3%, 7.2%, 8.9%, and 10.5%) were used under four different excess air ratios (1, 1.2, 1.5, and 1.8) with 1500rpm of engine speed. Hydrogen injection timing was optimized to form a stratified mixture. The result obtained demonstrated that flame developing duration and combustion duration were reduced after hydrogen added, the engine performed higher in-cylinder pressure and heat release rate with the increase of hydrogen proportion as well as effective thermal efficiency. Due to the improvement on combustion rate, the MBT was retarded close to the TDC. Cyclical variation was reduced and lean-burn limit was extended. In addition, HC and CO emissions were reduced while NOx emission increased with addition of hydrogen. The PM emission remains a low level.

Influence of intake geometry variations on in-cylinder flow and flow–spray interactions in a stratified direct-injection spark-ignition engine captured by time-resolved particle image velocimetry

Time-resolved particle image velocimetry and Mie-scattering of fuel droplets at 16 kHz were used to capture simultaneously the temporal evolution of the in-cylinder flow field and spray formation within a direct-injection spark-ignition engine. The engine was operated in stratified combustion mode, with stratified mixtures created by a triple injection late in the compression stroke. The impact of geometric variation of the intake port on in-cylinder flow and flow–spray interactions was investigated, focusing on the second injection, since it provides ignitable mixtures at the time of ignition and is subject to strong fluctuations, rather than the first injection, which is very reproducible. Flow field statistics conditioned on the spray shape of the second injection revealed regions with macroscopic cycle-to-cycle flow variations, which correlated with the spray for all recorded cycles. The flow–spray interaction was traced back to before the first injection using correlation analysis, which revealed that cycle-to-cycle fluctuations of the large-scale tumble vortex had a big impact on the spray shape of the second injection, while the first injection was unaffected. This indicates that the origin of the spray fluctuations may be during intake. Despite significant flow modifications due to the intake port geometry variation, fluctuation levels of the second injection were the same for both geometries, that is, spray fluctuations were not sensitive to the geometric change.

Validation and recommendations for FLACS CFD and engineering approaches to model hydrogen vented explosions: Effects of concentration, obstruction vent area and ignition position

Explosion venting is commonly used in the process industries as a prevention solution to protect equipment or buildings against excessive internal pressure caused by an internal explosion. In practical cases, for instance in the presence of complex 3D obstructions or for stratified flammable mixtures, analytical engineering models fail. At the opposite, for simple situations, engineering models are sufficient and could give an immediate estimation of the overpressure generated. As a consequence, CFD and engineering are two complementary solutions but they have to be carefully validated. This article is dedicated to the validation of FLACS CFD code and an engineering tool for the modeling of vented explosions by comparison with recent published experimental results. Recommendations and good practices are suggested for the applications of both FLACS CFD and engineering models.

A new predictive multi-zone model for HCCI engine combustion

This work introduces a new predictive multi-zone model for the description of combustion in Homogeneous Charge Compression Ignition (HCCI) engines. The model exploits the existing OpenSMOKE++ computational suite to handle detailed kinetic mechanisms, providing reliable predictions of the in-cylinder auto-ignition processes. All the elements with a significant impact on the combustion performances and emissions, like turbulence, heat and mass exchanges, crevices, residual burned gases, thermal and feed stratification are taken into account. Compared to other computational approaches, this model improves the description of mixture stratification phenomena by coupling a wall heat transfer model derived from CFD application with a proper turbulence model. Furthermore, the calibration of this multi-zone model requires only three parameters, which can be derived from a non-reactive CFD simulation: these adaptive variables depend only on the engine geometry and remain fixed across a wide range of operating conditions, allowing the prediction of auto-ignition, pressure traces and pollutants. This computational framework enables the use of detail kinetic mechanisms, as well as Rate of Production Analysis (RoPA) and Sensitivity Analysis (SA) to investigate the complex chemistry involved in the auto-ignition and the pollutants formation processes. In the final sections of the paper, these capabilities are demonstrated through the comparison with experimental data.

Effect of mixture flow stratification on premixed flame structure and emissions under counter-rotating swirl burner configuration

An investigation of the flame structure and emission performance of stratified swirl methane/air flames was performed by using a double-annulus counter-rotating premixed swirl burner. Stratification of the flow and mixtures were established by varying the bulk air flow rates and mixture equivalence ratios between the inner and outer annuli. Two distinct flame fronts were stabilised at the burner outlet, separated by a shear layer due to velocity differences. Higher swirl flow in the inner annulus generates an elongated and enlarged area of flame reaction zone due to increased flame intensity, as the flame shape is strongly dependent on the velocity magnitude exiting the annulus. Mixture and flow stratification affect local emissions. A richer mixture stratification within the inner channel at 70:30 flow split results in 91% and 49% higher emission rates of NO and CO respectively compared to premixed arrangement, in spite generally aiding flame stability. Enrichment of the outer annulus at 70:30 split flow shows only slightly higher levels of NO and CO emissions by 3% and 9% respectively compared to a homogenous mixture.

E25 stratified torch ignition engine performance, CO2 emission and combustion analysis

Vehicular emissions significantly increase atmospheric air pollution and the greenhouse effect. This fact associated with the fast growth of the global motor vehicle fleet demands technological solutions from the scientific community in order to achieve a decrease in fuel consumption and CO2 emission, especially of fossil fuels to comply with future legislation. To meet this goal, a prototype stratified torch ignition engine was designed from a commercial baseline engine. In this system, the combustion starts in a pre-combustion chamber where the pressure increase pushes the combustion jet flames through a calibrated nozzle to be precisely targeted into the main chamber. These combustion jet flames are endowed with high thermal and kinetic energy being able to promote a stable lean combustion process. The high kinetic and thermal energy of the combustion jet flame results from the load stratification. This is carried out through direct fuel injection in the pre-combustion chamber by means of a prototype gasoline direct injector (GDI) developed for low fuel flow rate. During the compression stroke, lean mixture coming from the main chamber is forced into the pre-combustion chamber and, a few degrees before the spark timing, fuel is injected into the pre-combustion chamber aiming at forming a slightly rich mixture cloud around the spark plug which is suitable for the ignition and kernel development. The performance of the torch ignition engine running with E25 is presented for different mixture stratification levels, engine speed and load. The performance data such as combustion phasing, specific fuel consumption, thermal efficiency and the specific emissions of CO2 are carefully analyzed and discussed in this paper. The results obtained in this work show a significant increase in the torch ignition engine’s performance in comparison with the baseline engine which was used as a workhorse for the prototype engine construction.

LES of the Cambridge Stratified Swirl Burner using a Sub-grid pdf Approach

The sub-grid scale probability density function equation is rearranged in order to separate the resolved and sub-grid-scale (sgs) contributions to the sgs mixing term. This allows modelling that is consistent with the limiting case of negligible sub-grid scale variations, a property required for applications to laboratory premixed flames. The new method is applied to the Cambridge Stratified Swirl Burner for 6 operating conditions, 2 isothermal and 4 burning, with varying degrees of swirl and mixture stratification. The simulations are performed with the Large Eddy Simulation (LES) code BOFFIN in which the modelled pdf transport equation is solved using the Eulerian stochastic field method. Eight stochastic fields are used to account for the influence of the sub-grid fluctuations and the chemistry is modelled with a reduced version of the GRI 3.0 mechanism for methane involving 19 species and 15 reaction steps. The simulated velocities for both the isothermal and burning cases show good agreement with the experimental data. The measured temperature and major species profiles are also reproduced to a good accuracy.

Efficiency improvement of a spark-ignition engine at full load conditions using exhaust gas recirculation and variable geometry turbocharger – Numerical study

The numerical analysis of performance of a four cylinder highly boosted spark-ignition engine at full load is described in this paper, with the research focused on introducing high pressure exhaust gas recirculation for control of engine limiting factors such as knock, turbine inlet temperature and cyclic variability. For this analysis the cycle-simulation model which includes modeling of the entire engine flow path, early flame kernel growth, mixture stratification, turbulent combustion, in-cylinder turbulence, knock and cyclic variability was applied. The cylinder sub-models such as ignition, turbulence and combustion were validated by using the experimental results of a naturally aspirated multi cylinder spark-ignition engine. The high load operation, which served as a benchmark value, was obtained by a standard procedure used in calibration of engines, i.e. operation with fuel enrichment and without exhaust gas recirculation. By introducing exhaust gas recirculation and by optimizing other engine operating parameters, the influence of exhaust gas recirculation on engine performance is obtained. The optimum operating parameters, such as spark advance, intake pressure, air to fuel ratio, were found to meet the imposed requirements in terms of fuel consumption, knock occurrence, exhaust gas temperature and variation of indicated mean effective pressure. By comparing the results of the base point with the results that used exhaust gas recirculation the improvement in fuel consumption of 8.7%, 11.2% and 1.5% at engine speeds of 2000rpm, 3500rpm and 5000rpm is obtained. Additionally, by using the presented numerical methodology the influence of the specific operating parameter on the overall behavior of the complex charging system was shown.