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Advanced Technologies for the Optimization of Internal Combustion Engines

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A special issue of Applied Sciences (ISSN 2076-3417). This special issue belongs to the section "Mechanical Engineering".

Deadline for manuscript submissions: closed (31 May 2021) | Viewed by 29567

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Special Issue Editors

Dr. Cinzia Tornatore

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Guest Editor

Institute of Science and Technology for Sustainable Energy and Mobility (STEMS-CNR), Italian National Research Council, via Marconi, 4-80125 Napoli, Italy
Interests: internal combustion engines; emissions; combustion; optical diagnostics
Special Issues, Collections and Topics in MDPI journals

Dr. Luca Marchitto

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Guest Editor

Institute of Science and Technology for Sustainable Energy and Mobility (STEMS-CNR), Italian National Research Council, 80125 Napoli, Italy
Interests: internal combustion engines; emissions; combustion; marine engines
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear colleagues,

At the present time, there are still no real options that can totally replace the internal combustion (IC) engine over the entire range of its applications. In the short-to-medium term, transportation on-road and off-road will most likely be characterized by a mix of solutions including strongly electrified powertrain configurations, as well as conventional vehicles powered by IC engines. The combustion engine will still play a central role; for this reason, there is a pressing need for its further optimization in term of thermal efficiency and pollutant emission. This goal can be achieved through more efficient and environment-friendly technologies.

The aim of this Special Issue is to put together the recent research in advanced technologies for the optimization of internal combustion engines in order to help the scientific community to address the efforts towards the development of higher-power engines with lower fuel consumption and pollutant emissions. We invite researchers to submit both original research and review articles that explore this theme. Innovative experimental and numerical works are welcome. Topics of interest for this Special Issue include (but are not limited to):

Advanced ignition and combustion systems;
Advanced fuel injection systems;
Novel fuel spray technologies;
Alternative fuels;
Alternative combustion processes;
Combustion engine performance;
Exhaust emissions reduction;
Waste heat recovery;
Novel approaches of 0D, 1D, 3D simulation;
Hybrid powertrain.

Dr. Cinzia Tornatore
Dr. Luca Marchitto
Guest Editor

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Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Applied Sciences is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2400 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

advanced technologies
internal combustion engines
fuel consumption
alternative fuels
exhaust emissions
engine optimization
high-efficiency engines

Published Papers (12 papers)

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Editorial

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3 pages, 174 KiB

Open AccessEditorial

Advanced Technologies for the Optimization of Internal Combustion Engines

by Cinzia Tornatore and Luca Marchitto

Appl. Sci. 2021, 11(22), 10842; https://0-doi-org.brum.beds.ac.uk/10.3390/app112210842 - 17 Nov 2021

Cited by 4 | Viewed by 2443

Abstract

Even in a scenario where electric vehicles gain market share and the sale of internal combustion engines is gradually reduced, at the present time, there are still no real options that can totally replace the internal combustion (IC) engine over the entire range [...] Read more.

(This article belongs to the Special Issue Advanced Technologies for the Optimization of Internal Combustion Engines)

Research

Jump to: Editorial

12 pages, 1796 KiB

Open AccessArticle

Performance and Emissions of a Spark Ignition Engine Fueled with Water-in-Gasoline Emulsion Produced through Micro-Channels Emulsification

by Cinzia Tornatore, Luca Marchitto, Luigi Teodosio, Patrizio Massoli and Jérôme Bellettre

Appl. Sci. 2021, 11(20), 9453; https://0-doi-org.brum.beds.ac.uk/10.3390/app11209453 - 12 Oct 2021

Cited by 4 | Viewed by 1454

Abstract

This paper presents an experimental study investigating the effects of water-in-gasoline emulsion (WiGE) on the performance and emissions of a turbocharged PFI spark-ignition engine. The emulsions were produced through a micro-channels emulsifier, potentially capable to work inline, without addition of surfactants. Measurements were performed at a 3000 rpm speed and net Indicated Mean Effective Pressure (IMEP) of 16 bar: the engine point representative of commercial ECU map was chosen as reference. In this condition, the engine, fueled with gasoline, runs overfueled (λ = 0.9) to preserve the integrity of the turbocharger from excessive temperature, and the spark timing corresponds to the knock limit. Starting from the reference point, two different water contents in emulsion were tested, 10% and 20% by volume, respectively. For each selected emulsion, at λ = 0.9, the spark timing was advanced from the reference point value to the new knock limit, controlling the IMEP at a constant level. Further, the cooling effect of water evaporation in WiGE allowed it to work at stoichiometric condition, with evident benefits on the fuel economy. Main outcomes highlight fuel consumption improvements of about 7% under stoichiometric mixture and optimized spark timing, while avoiding an excessive increase in turbine thermal stress. Emulsions induce a slight worsening in the HC emissions, arising from the relative impact on combustion development. On the other hand, at stoichiometric condition, HC and CO emissions drop with a corresponding increase in NO. Full article

(This article belongs to the Special Issue Advanced Technologies for the Optimization of Internal Combustion Engines)

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21 pages, 45181 KiB

Open AccessArticle

0D/1D Thermo-Fluid Dynamic Modeling Tools for the Simulation of Driving Cycles and the Optimization of IC Engine Performances and Emissions

by Andrea Marinoni, Matteo Tamborski, Tarcisio Cerri, Gianluca Montenegro, Gianluca D’Errico, Angelo Onorati, Emanuele Piatti and Enrico Ernesto Pisoni

Appl. Sci. 2021, 11(17), 8125; https://0-doi-org.brum.beds.ac.uk/10.3390/app11178125 - 01 Sep 2021

Cited by 9 | Viewed by 3587

Abstract

The prediction of internal combustion engine performance and emissions in real driving conditions is getting more and more important due to the upcoming stricter regulations. This work aims at introducing and validating a new transient simulation methodology of an ICE coupled to a hybrid architecture vehicle, getting closer to real-time calculations. A one-dimensional computational fluid dynamic software has been used and suitably coupled to a vehicle dynamics model in a user function framework integrated within a Simulink^® environment. A six-cylinder diesel engine has been modeled by means of the 1D tool and cylinder-out emissions have been compared to experimental data. The measurements available have been used also to calibrate the combustion model. The developed 1D engine model has been then used to perform driving cycle simulations considering the vehicle dynamics and the coupling with the energy storage unit in the hybrid mode. The map-based approach along with the vehicle simulation tool has also been used to perform the same simulation and the two results are compared to evaluate the accuracy of each approach. In this framework, to achieve the best simulation performance in terms of computational time over simulated time ratio, the 1D engine model has been used in a configuration with a very coarse mesh. Results have shown that despite the high mesh spacing used the accuracy of the wave dynamics prediction was not affected in a significant way, whereas a remarkable speed-up factor was achieved. This means that a crank angle resolution approach to the vehicle simulation is a viable and accurate strategy to predict the engine emission during any driving cycle with a computation effort compatible with the tight schedule of a design process. Full article

(This article belongs to the Special Issue Advanced Technologies for the Optimization of Internal Combustion Engines)

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16 pages, 3372 KiB

Open AccessArticle

Optimization of Design and Technology of Injector Nozzles in Terms of Minimizing Energy Losses on Friction in Compression Ignition Engines

by Jan Monieta and Lech Kasyk

Appl. Sci. 2021, 11(16), 7341; https://0-doi-org.brum.beds.ac.uk/10.3390/app11167341 - 10 Aug 2021

Cited by 6 | Viewed by 2593

Abstract

The operation of injection apparatus in self-ignition engines results from the design, manufacturing technology and wear and tear during operation. The technical state of the injector apparatus significantly affects the engine performance, fuel consumption, toxicity and smoke opacity of outlet gases. The most unreliable element of the injection apparatus is the injector nozzle, the quality of which depends on the quality of construction and production, operating conditions and the of the fuels used, etc. One of the design parameters of the injector nozzles, determining the technical state is the geometry of the nozzle holes. An attempt was made to optimize the selection of the dimensions and surface condition of the spray holes to significantly affect the flow properties of the injector nozzles and, consequently, to decide on the size and form of fuel dosed streams to individual cylinders of a self-ignition engine and the quality of fuel atomization. In work, a simulation model was developed, and the pressure losses and the mass fluid of the injected fuel were minimized for selected significant geometric features, taking into account the influence of operating conditions. With the use of Mathematica software, simulation optimization methods and methods based on evolutionary algorithms were elaborated. Full article

(This article belongs to the Special Issue Advanced Technologies for the Optimization of Internal Combustion Engines)

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Graphical abstract

25 pages, 2979 KiB

Open AccessFeature PaperArticle

Effect of Cylinder-by-Cylinder Variation on Performance and Gaseous Emissions of a PFI Spark Ignition Engine: Experimental and 1D Numerical Study

by Luigi Teodosio, Luca Marchitto, Cinzia Tornatore, Fabio Bozza and Gerardo Valentino

Appl. Sci. 2021, 11(13), 6035; https://0-doi-org.brum.beds.ac.uk/10.3390/app11136035 - 29 Jun 2021

Cited by 5 | Viewed by 2014

Abstract

Combustion stability, engine efficiency and emissions in a multi-cylinder spark-ignition internal combustion engines can be improved through the advanced control and optimization of individual cylinder operation. In this work, experimental and numerical analyses were carried out on a twin-cylinder turbocharged port fuel injection (PFI) spark-ignition engine to evaluate the influence of cylinder-by-cylinder variation on performance and pollutant emissions. In a first stage, experimental tests are performed on the engine at different speed/load points and exhaust gas recirculation (EGR) rates, covering operating conditions typical of Worldwide harmonized Light-duty vehicles Test Cycle (WLTC). Measurements highlighted relevant differences in combustion evolution between cylinders, mainly due to non-uniform effective in-cylinder air/fuel ratio. Experimental data are utilized to validate a one-dimensional (1D) engine model, enhanced with user-defined sub-models of turbulence, combustion, heat transfer and noxious emissions. The model shows a satisfactory accuracy in reproducing the combustion evolution in each cylinder and the temperature of exhaust gases at turbine inlet. The pollutant species (HC, CO and NOx) predicted by the model show a good agreement with the ones measured at engine exhaust. Furthermore, the impact of cylinder-by-cylinder variation on gaseous emissions is also satisfactorily reproduced. The novel contribution of present work mainly consists in the extended numerical/experimental analysis on the effects of cylinder-by-cylinder variation on performance and emissions of spark-ignition engines. The proposed numerical methodology represents a valuable tool to support the engine design and calibration, with the aim to improve both performance and emissions. Full article

(This article belongs to the Special Issue Advanced Technologies for the Optimization of Internal Combustion Engines)

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30 pages, 15271 KiB

Open AccessArticle

Investigations for a Trajectory Variation to Improve the Energy Conversion for a Four-Stroke Free-Piston Engine

by Robin Tempelhagen, Andreas Gerlach, Sebastian Benecke, Kevin Klepatz, Roberto Leidhold and Hermann Rottengruber

Appl. Sci. 2021, 11(13), 5981; https://0-doi-org.brum.beds.ac.uk/10.3390/app11135981 - 27 Jun 2021

Cited by 1 | Viewed by 1512

Abstract

Internal combustion engines with a crankshaft have been successfully developed for many years. They are lacking in the fact that the piston trajectory, i.e., position as a function of time, is limited by the crankshaft motion law. Position-controlled electric linear machines directly coupled to the piston allow to realize free-piston engines. Unlike the crankshaft-based engines, they allow for a higher degree of freedom in shaping the piston trajectory, including adaptive compression ratios, which enables optimal operation with alternative fuels. The possibility of adapting the stroke course results in new degrees of freedom with which the combustion process can be optimized. In this work, four-stroke trajectories with different amplitudes and piston dynamics have been proposed and analyzed regarding efficiency. A simulation model was created based on experimental measurements for testing the proposed trajectories. It could be proved that the variation of the trajectory resulted in an improvement of the overall efficiency. The trajectories were described analytically so that they can be used for a prototype in a future work. Full article

(This article belongs to the Special Issue Advanced Technologies for the Optimization of Internal Combustion Engines)

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16 pages, 5568 KiB

Open AccessFeature PaperArticle

Experimental Analysis of Water Pressure and Temperature Influence on Atomization and Evolution of a Port Water Injection Spray

by Lucio Postrioti, Gabriele Brizi and Gian Marco Finori

Appl. Sci. 2021, 11(13), 5980; https://0-doi-org.brum.beds.ac.uk/10.3390/app11135980 - 27 Jun 2021

Cited by 3 | Viewed by 1793

Abstract

Port water injection (PWI) is considered one of the most promising technologies to actively control the increased knock tendency of modern gasoline direct injection (GDI) engines, which are rapidly evolving with the adoption of high compression ratios and increased brake mean effective pressure levels in the effort to improve their thermal efficiency. For PWI technology, appropriately matching the spray evolution and the intake system design along with obtaining a high spray atomization quality, are crucial tasks for promoting water evaporation so as to effectively cool down the air charge with moderate water consumption and lubricant dilution drawbacks. In the present paper, a detailed experimental analysis of a low-pressure water spray is presented, covering a lack of experimental data on automotive PWI systems. Phase doppler anemometry and fast-shutter spray imaging allowed us to investigate the influence exerted by the injection pressure level and by the water temperature on spray drop size and global shape, obtaining a complete database to be used for the optimization of PWI systems. The obtained results evidence how significant benefits in terms of atomization quality can be obtained by adopting injection pressure and water temperature levels compliant with standard low injection pressure technologies. Full article

(This article belongs to the Special Issue Advanced Technologies for the Optimization of Internal Combustion Engines)

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28 pages, 53454 KiB

Open AccessArticle

Combustion and Performance Evaluation of a Spark Ignition Engine Operating with Acetone–Butanol–Ethanol and Hydroxy

by Wilson Guillin-Estrada, Daniel Maestre-Cambronel, Antonio Bula-Silvera, Arturo Gonzalez-Quiroga and Jorge Duarte-Forero

Appl. Sci. 2021, 11(11), 5282; https://0-doi-org.brum.beds.ac.uk/10.3390/app11115282 - 07 Jun 2021

Cited by 12 | Viewed by 2867

Abstract

Alternative fuels for internal combustion engines (ICE) emerge as a promising solution for a more sustainable operation. This work assesses combustion and performance of the dual-fuel operation in the spark ignition (SI) engine that simultaneously integrates acetone–butanol–ethanol (ABE) and hydroxy (HHO) doping. The study evaluates four fuel blends that combine ABE 5, ABE 10, and an HHO volumetric flow rate of 0.4 LPM. The standalone gasoline operation served as the baseline for comparison. We constructed an experimental test bench to assess operation conditions, fuel mode, and emissions characteristics of a 3.5 kW-YAMAHA engine coupled to an alkaline electrolyzer. The study proposes thermodynamic and combustion models to evaluate the performance of the dual-fuel operation based on in-cylinder pressure, heat release rate, combustion temperature, fuel properties, energy distribution, and emissions levels. Results indicate that ABE in the fuel blends reduces in-cylinder pressure by 10–15% compared to the baseline fuel. In contrast, HHO boosted in-cylinder pressure up to 20%. The heat release rate and combustion temperature follow the same trend, corroborating that oxygen enrichment enhances gasoline combustion. The standalone ABE operation raises fuel consumption by around 10–25

g ∙ {kWh}^{- 1}

compared to gasoline depending on the load, whereas HHO decreases fuel consumption by around 25%. The dual-fuel operation shows potential for mitigating CO, HC, and smoke emissions, although NOx emissions increased. The implementation of dual-fuel operation in SI engines represents a valuable tool for controlling emissions and reducing fuel consumption while maintaining combustion performance and thermal efficiency. Full article

(This article belongs to the Special Issue Advanced Technologies for the Optimization of Internal Combustion Engines)

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31 pages, 11712 KiB

Open AccessArticle

Development of a Computationally Efficient Tabulated Chemistry Solver for Internal Combustion Engine Optimization Using Stochastic Reactor Models

by Andrea Matrisciano, Tim Franken, Laura Catalina Gonzales Mestre, Anders Borg and Fabian Mauss

Appl. Sci. 2020, 10(24), 8979; https://0-doi-org.brum.beds.ac.uk/10.3390/app10248979 - 16 Dec 2020

Cited by 14 | Viewed by 2218

Abstract

The use of chemical kinetic mechanisms in computer aided engineering tools for internal combustion engine simulations is of high importance for studying and predicting pollutant formation of conventional and alternative fuels. However, usage of complex reaction schemes is accompanied by high computational cost in 0-D, 1-D and 3-D computational fluid dynamics frameworks. The present work aims to address this challenge and allow broader deployment of detailed chemistry-based simulations, such as in multi-objective engine optimization campaigns. A fast-running tabulated chemistry solver coupled to a 0-D probability density function-based approach for the modelling of compression and spark ignition engine combustion is proposed. A stochastic reactor engine model has been extended with a progress variable-based framework, allowing the use of pre-calculated auto-ignition tables instead of solving the chemical reactions on-the-fly. As a first validation step, the tabulated chemistry-based solver is assessed against the online chemistry solver under constant pressure reactor conditions. Secondly, performance and accuracy targets of the progress variable-based solver are verified using stochastic reactor models under compression and spark ignition engine conditions. Detailed multicomponent mechanisms comprising up to 475 species are employed in both the tabulated and online chemistry simulation campaigns. The proposed progress variable-based solver proved to be in good agreement with the detailed online chemistry one in terms of combustion performance as well as engine-out emission predictions (CO, CO₂, NO and unburned hydrocarbons). Concerning computational performances, the newly proposed solver delivers remarkable speed-ups (up to four orders of magnitude) when compared to the online chemistry simulations. In turn, the new solver allows the stochastic reactor model to be computationally competitive with much lower order modeling approaches (i.e., Vibe-based models). It also makes the stochastic reactor model a feasible computer aided engineering framework of choice for multi-objective engine optimization campaigns. Full article

(This article belongs to the Special Issue Advanced Technologies for the Optimization of Internal Combustion Engines)

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17 pages, 1225 KiB

Open AccessArticle

Influence of Pre-Turbine Small-Sized Oxidation Catalyst on Engine Performance and Emissions under Driving Conditions

by José Ramón Serrano, Pedro Piqueras, Joaquín De la Morena and María José Ruiz

Appl. Sci. 2020, 10(21), 7714; https://0-doi-org.brum.beds.ac.uk/10.3390/app10217714 - 31 Oct 2020

Cited by 2 | Viewed by 1656

Abstract

The earlier activation of the catalytic converters in internal combustion engines is becoming highly challenging due to the reduction in exhaust gas temperature caused by the application of

{CO}_{2}

reduction technologies. In this context, the use of pre-turbine catalysts arises as a [...] Read more.

The earlier activation of the catalytic converters in internal combustion engines is becoming highly challenging due to the reduction in exhaust gas temperature caused by the application of

{CO}_{2}

reduction technologies. In this context, the use of pre-turbine catalysts arises as a potential way to increase the conversion efficiency of the exhaust aftertreatment system. In this work, a small-sized oxidation catalyst consisting of a honeycomb thin-wall metallic substrate was placed upstream of the turbine to benefit from the higher temperature and pressure prior to the turbine expansion. The change in engine performance and emissions in comparison to the baseline configuration are analyzed under driving conditions. As an individual element, the pre-turbine catalyst contributed positively with a relevant increase in the overall CO and HC conversion efficiency. However, its placement produced secondary effects on the engine and baseline aftertreatment response. Although small-sized monoliths are advantageous to minimize the thermal inertia impact on the turbocharger lag, the catalyst cross-section is in trade-off with the additional pressure drop that the monolith causes. As a result, the higher exhaust manifold pressure in pre-turbine pre-catalyst configuration caused a fuel consumption increase higher than 3% while the engine-out CO and HC emissions did around 50%. These increments were not completely offset despite the high pre-turbine pre-catalyst conversion efficiency (>40%) because the partial abatement of the emissions in this device conditioned the performance of the close-coupled oxidation catalyst. Full article

(This article belongs to the Special Issue Advanced Technologies for the Optimization of Internal Combustion Engines)

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20 pages, 3965 KiB

Open AccessFeature PaperArticle

Experimental Study of the Effect of Hydrotreated Vegetable Oil and Oxymethylene Ethers on Main Spray and Combustion Characteristics under Engine Combustion Network Spray A Conditions

by José V. Pastor, José M. García-Oliver, Carlos Micó, Alba A. García-Carrero and Arantzazu Gómez

Appl. Sci. 2020, 10(16), 5460; https://0-doi-org.brum.beds.ac.uk/10.3390/app10165460 - 07 Aug 2020

Cited by 24 | Viewed by 3050

Abstract

The stringent emission regulations have motivated the development of cleaner fuels as diesel surrogates. However, their different physical-chemical properties make the study of their behavior in compression ignition engines essential. In this sense, optical techniques are a very effective tool for determining the spray evolution and combustion characteristics occurring in the combustion chamber. In this work, quantitative parameters describing the evolution of diesel-like sprays such as liquid length, spray penetration, ignition delay, lift-off length and flame penetration as well as the soot formation were tested in a constant high pressure and high temperature installation using schlieren, OH∗ chemiluminescence and diffused back-illumination extinction imaging techniques. Boundary conditions such as rail pressure, chamber density and temperature were defined using guidelines from the Engine Combustion Network (ECN). Two paraffinic fuels (dodecane and a renewable hydrotreated vegetable oil (HVO)) and two oxygenated fuels (methylal identified as OME₁ and a blend of oxymethylene ethers, identified as OME_x) were tested and compared to a conventional diesel fuel used as reference. Results showed that paraffinic fuels and OME_x sprays have similar behavior in terms of global combustion metrics. In the case of OME₁, a shorter liquid length, but longer ignition delay time and flame lift-off length were observed. However, in terms of soot formation, a big difference between paraffinic and oxygenated fuels could be appreciated. While paraffinic fuels did not show any significant decrease of soot formation when compared to diesel fuel, soot formed by OME₁ and OME_x was below the detection threshold in all tested conditions. Full article

(This article belongs to the Special Issue Advanced Technologies for the Optimization of Internal Combustion Engines)

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30 pages, 12587 KiB

Open AccessArticle

An Analysis on the Effects of the Fuel Injection Rate Shape of the Diesel Spray Mixing Process Using a Numerical Simulation

by Intarat Naruemon, Long Liu, Dai Liu, Xiuzhen Ma and Keiya Nishida

Appl. Sci. 2020, 10(14), 4983; https://0-doi-org.brum.beds.ac.uk/10.3390/app10144983 - 20 Jul 2020

Cited by 11 | Viewed by 2677

Abstract

In diesel engines, fuel mixing is an important process in determining the combustion efficiency and emissions level. One of the measures used to achieve fuel mixing is controlling the nature and behavior of the fuel spray by shaping the injection rate. The mechanism underlying the behavior of the spray with varying injection rates before the start of combustion is not fully understood. Therefore, in this research, the fuel injection rate shape is investigated to assess the spraying and mixing behavior. Diesel sprays with different ambient temperatures and injection pressures are modeled using the CONVERGE-CFD software. The validation is performed based on experimental data from an Engine Combustion Network (ECN). The verified models are then used to analyze the characteristics of the diesel spray before and after the end-of-injection (EOI) with four fuel injection rate shapes, including a rectangular injection rate shape (RECT), a quick increase gradual decrease injection rate shape (QIGD), a gradual increase gradual decrease injection rate shape (GIGD), and a gradual increase quick decrease injection rate shape (GIQD). The spray vapor penetrations, liquid lengths, evaporation ratios, Sauter mean diameter (SMDs), distributions of turbulence kinetic energy, temperatures, and equivalence ratios were compared under different injection rate shapes. The results show that the QIGD injection rate shape can enhance mixing during injection, while the GIQD injection rate shape can achieve better mixing after the EOI. Full article

(This article belongs to the Special Issue Advanced Technologies for the Optimization of Internal Combustion Engines)

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