The piston ring-cylinder liner (PRCL) is one of the most important parts of marine diesel engines and contributes 25% to 50% of total friction loss. The lubrication simulation analysis of the PRCL system is a challenging task. Complete understanding and precise prediction of lubrication loads is a key to understanding the friction behavior of PRCL systems as the accuracy of the friction prediction

Hydrotreated vegetable oil (HVO), a glycerol-derived biofuel (blended with diesel fuel at 20% v/v, Mo·bio®) and biodiesel produced through the esterification of residual free fatty acids from the palm oil industry (pure and blended with diesel fuel at 20% v/v), all of them considered as advanced biofuels as defined in the Directive EU/2018/2001, were tested in a Euro 6 diesel vehicle equipped with

This work presents a computational study about the effect of different fossil fuels (Diesel and GTL) and renewable (Farnesane and Biodiesel) on the characteristics of the nozzle fuel internal flow (speed flow, cavitation, mass flow rate and discharge coefficient). This investigation was focused on the pass of fuel from the volume around the tip of the injector needle to the nozzle holes. Several engine-operating

Stoichiometric industrial natural gas engines rely on robust design to achieve consumer driven up-time requirements. Key to this design are exhaust components that are able to withstand high combustion temperatures found in this type of natural gas engine. The issue of exhaust component durability can be addressed by making improvements to materials and coatings or decreasing combustion temperatures

Soot engine-out emissions are no longer a prerogative of Diesel engines. Emission regulations related to Gasoline units aim to curb the soot emissions along with other pollutants. In this scenario, Computational Fluid Dynamics (CFD) is a very promising research and development tool to explore the influence of engine design and operational parameters, as well as of the fuel chemical nature, on the particulate

This study assesses the predictive capability of the ZGB (Zwart-Gerber-Belamri) cavitation model with the RANS (Reynolds Averaged Navier-Stokes), the realizable k-epsilon turbulence model, and compressibility of gas/liquid models for cavitation simulation in a multi-hole fuel injector at different cavitation numbers (CN) for diesel and biodiesel fuels. The prediction results were assessed quantitatively

Cavitation in fuel injectors occurs in the nozzle region where local pressure drops below the fuel saturation pressure. The pressure drop might simultaneously induce the formation of gas bubbles such as nitrogen dissolved in the fuel, also known as pseudo-cavitation. A new cavitation model has been developed that accounts for the nitrogen bubbles separation from the fuel stream by accounting for the

Aircraft contrails contribute to climate change through global radiative forcing. As part of the general effort aimed at developing reliable decision-making tools, this paper demonstrates the feasibility of implementing a Lagrangian ice microphysical module in a commercial CFD code to characterize the early development of near-field contrails. While engine jets are highly parameterized in most existing

Optimising the parameters of valve timing and fuel system can promote the applications of high-power diesel engines that have high efficiency and low emissions. Nevertheless, the problem of the piston’s thermal load needs to be considered. In this paper, a calculation model for the working process of a high-power diesel engine and a finite element model of the piston’s thermal load were established

Laser surface texturing technology including the steps of surface pre-processing, laser texturing, and surface post-polishing was utilized to process typical micro-dimples(diameter 50 μm, depth 8 μm, and area ratio 10%) on the cylinder liner surface in a production engine. By conducting the reciprocating friction tests on a friction-wear tester, the instantaneous friction force of the real cylinder

The sensors abnormalities, faults, failure detection and diagnosis for marine engines are considered crucial for ensuring the engine safe and smooth operation. The development of such system(s) is typically based on the manufacturers experience on sensors and actuators faults and failure events. This study aims to introduce a novel methodology for the sensors diagnostics and health management in marine

The ability to accurately predict the outcome of the drop/wall interaction is essential to engine spray combustion modeling. In this paper, the process of fuel drop impact on a wet wall was simulated using a numerical method based on smoothed particle hydrodynamics (SPH). The present numerical method was first validated using experimental data on the crown height and crown diameter resulting from water

The European Union (EU) has recently adopted new directives to reduce the level of pollutant emissions from non-road mobile machinery engines. The main scope of project RIVER for which this study is relating is to develop possible solutions to achieve nitrogen-free combustion and zero-carbon emissions in diesel engines. RIVER aims to apply oxy-fuel combustion with Carbon Capture and Storage (CCS) technology

As requirements for continuously improving internal combustion engine fuel economy with satisfactory emissions, model-based control strategies are often used to optimize the combustion process. To apply advanced control techniques for closed-loop engine combustion control, control-oriented engine combustion models are necessary and they are physics-based, accurate enough for model-based control, computationally

Ethanol, n-propanol, isopropanol, n-butanol, isobutanol, and sec-butanol are six potential carbon-neutral fuels of the future. One application of these carbon-neutral fuels is in high-dilution spark ignition. To understand the potential of these fuels in high-dilution spark ignition, this work experimentally determines the spark ignition lean flammability limit of each fuel with no external, cooled

The effect of split injection on the fuel spray and combustion processes in a rapid compression and expansion machine was investigated using the visualization process. A two-dimensional piston cavity, designed with the cross section of a reentrant piston, was installed in the combustion chamber to observe the combustion process from the lateral side. Combustion experiments were conducted with injection

In order to describe the microstructure of the porous wall of a gasoline particulate filter (GPF), a pore size distribution based on a probability density function (PDF) and a non-uniform porosity distribution are introduced. The dynamic process of deep-bed filtration in GPF with inhomogeneous wall structure is studied, considering different particle size distributions (PSDs). The results show that

Renewable fuels are continuously being refined/ upgraded for automotive applications to reduce dependence on conventional fossil fuels. However, optimized use of these renewable fuels in existing and new engines/ vehicles requires comprehensive characterization and understanding of spray atomization and fuel-air mixture formation processes. Spray atomization and mixture formation depends on fuel injection

With the increasingly stringent environmental issues and regulations, there are higher requirements for improving engine performance and reducing pollution. Combining artificial neural network and particle swarm optimization algorithm to optimize the fuel consumption and emissions for micro-ignition dual-fuel engines. A model-based calibration scheme is maintained to reduce the number of experimental

Adverse effects of global warming due to the greenhouse gas emissions is changing the actual paradigm for the use energy resources. In the absence of a mid-term solution for reducing these emissions in transportation, internal combustion (IC) engines are going to coexist in the social spheres in the foreseeable future. Therefore, the study of other IC engine-related problems remains relevant to ensuring

To clarify the mechanisms of heat transfer on an engine wall is an important challenge because the heat loss on the wall is one of the dominant factors that limit the thermal efficiency. A thin-film resistance type heat flux sensor fabricated with Micro-Electro-Mechanical Systems (MEMS) technologies was applied to research on the heat transfer of an impinging diesel jet. The MEMS sensor had a high

The present work describes a numerical methodology and its experimental validation of the flow development inside and outside of the orifices during a pilot injection, dwelt time and the subsequent start of injection cycle. The compressible Navier-Stokes equations are numerically solved in a six-hole injector imposing realistic conditions of the needle valve movement and considering in addition a time-dependent

Kerosene based hydrocarbon fuels are preferred candidates for the source of energy due to its stable properties. Based on the requirement of the combustor and the growing concern over pollutant, kerosene based fuels are modified. The fuel under investigation is a modified form of kerosene with ultra-low sulphur content. The effect of temperature on modified kerosene is studied for viscosity, surface

As a non-intrusive method for engine working condition detection, the engine surface vibration contains rich information about the combustion process and has great potential for the closed-loop control of engines. However, the measured engine surface vibration signals are usually induced by combustion as well as non-combustion excitations and are difficult to be utilized directly. To evaluate some

The use of natural gas (NG) in dual-fuel heavy-duty engines has the potential to reduce pollutant and greenhouse gas (GHG) emissions from the transport sector when compared to the conventional diesel engines. However, NG composition and methane slip are of interest because both can adversely affect the benefits of NG as an alternative fuel, especially when considering GHG emissions. Therefore, this

Low air-flow diesel engine strategies are advantageous during low load operation to maintain temperatures of a warmed-up aftertreatment system (ATS) while reducing fuel consumption and engine-out emissions. This paper presents results at curb idle for internal EGR (iEGR) that demonstrate low airflow and reduced engine-out emissions during fuel-efficient ATS temperature maintenance operation. Internal

Exhaust-stream particulate matter (PM) emission from combustion sources such as internal combustion engines are typically characterized with modest temporal resolutions; however, in-cylinder investigations have demonstrated significant variability and the importance of individual cycles in transient PM emissions. Here, using a Fast Exhaust Nephelometer (FEN), a methodology is developed for measuring

Past experimental studies have shown that the needle valve of high-pressure diesel injectors undergoes lateral movement and deformation, while the continuous increase in injection pressure enlarges the gap of the needle valve assembly. Two different analytical models, considering or omitting this change are presented here, linking the geometries of the needle valve assembly with the magnitude of needle

It is a relevant objective in thermal physics and piston engine construction to develop technical solutions for controlling the gas dynamics and heat exchange of gas flows in the intake system of turbocharged engines in order to improve performance. The article presents other authors’ data on the improvement of processes in the gas exchange systems of piston engines. It also provides a description

It is well known that nozzle internal geometries affect the characteristics of diesel spray and combustion. However, despite a number of studies, the effects are difficult to generalize. It is also not clear which spray features are more important for combustion than others. To investigate these subjects, a comprehensive dataset on diesel spray combustion was obtained with 20 variations of multi-hole

Simulation calibration of modern engines to test bench measurements, mainly matching the indicated pressure curves in the combustion chamber, is a time consuming task that requires high user experience to manage a multitude of adjustment parameters. In the scope of this work an automated process for calibrating simulations at motored engine operating points is presented. This is achieved using characteristic

Premixed combustion strategies have the potential to achieve high thermal efficiency and to lower the engine-out emissions such as NOx. However, the combustion is initiated at several kernels which create high pressure gradients inside the cylinder. Similarly to knock in spark ignition engines, these gradients might be responsible of important pressure oscillations with a harmful potential for the

An on-going challenge with Gasoline direct injection (GDI) engines is achieving rapid activation of the exhaust catalyst during cold starts, in order to reduce the Nitrogen Oxide (NOx) emissions. Injecting late in the compression stroke, in the efforts to form a stratified mixture, provides the fuel insufficient time to be entrained with the surrounding charge. This results in locally fuel rich diffusion

The development of the injector nozzle is a dynamic area in regard of several technical aspects. At first, the internal flow influences the near-field spray characteristics via various phenomena such as cavitation and turbulence. However, these phenomena are not fully understood due to their extremely fast, complex and multiscale nature. Furthermore, it governs the spray targeting inside the combustion

Ozone (O3) was introduced into the intake air to control the ignition in a gasoline compression ignition (GCI) engine. An early fuel injection at −68 °CA ATDC was adopted to mix the fuel with the reactive O-radicals decomposed from the O3, before the reduction of the O-radicals due to their recombination would take place. The second injection was implemented near top dead center to optimize the profile

The effects of turbocharger (T/C) rotational inertia on engine and turbine performance under transient and steady engine conditions were analyzed in a 2.0 L 4-cylinder turbocharged-gasoline direct injection (T-GDI) engine. The test T/Cs consisted of heavy and light compressor wheels (C/W) and turbine wheels (T/W). The study was conducted in two research stages. First, transient engine load tests were

Cycle-to-cycle combustion variability in spark-ignition engines during normal operation is mainly caused by random perturbations of the in-cylinder conditions such as the flow velocity field, homogeneity of the air-fuel distribution, spark energy discharge, and turbulence intensity of the flame front. Such perturbations translate into the variability of the energy released observed at the end of the

This research aimed to investigate the lubricity and wear properties of ultra-low sulfur diesel fuel (ULSD) blended with biodiesel and doped with biodiesel-based organic compounds. In this work, neat n-dodecane served as a surrogate for ultra-low sulfur diesel fuel (ULSD), Fischer Tropsch, and renewable diesel fuels. Additionally, some pure hydrocarbons were also investigated for unsaturation and carbon

Dual-fuel (DF) engines, in which premixed natural gas and air in an open-type combustion chamber is ignited by diesel-fuel pilot sprays, have been more popular for marine use than pre-chamber spark ignition (PCSI) engines because of their superior durability. However, control of ignition and combustion in DF engines is more difficult than in PCSI engines. In this context, this study focuses on the

An experimental study was carried out to analyze the influence of different post-injection strategies on the regulated and unregulated emissions from a heavy-duty compression ignition (CI) diesel engine. FTIR (Fourier transform infrared spectroscopy) was used to measure and analyze the exhaust emissions which include regulated such as NOx, soot, and unregulated emissions including acetaldehyde, formaldehyde

In this paper the acoustic response of a combustion chamber is studied by assuming different pressure field excitation. The viscous effects on the combustion chamber and the finite impedance of the walls have been modeled with a first order system, which damps the resonance oscillation created by combustion. The characterization of the acoustic response of the combustion chamber has been used to identify

A set of two-cylinder engine concepts utilizing a supercharger and piston- or turbine-compounding were compared to a turbocharged engine modeled with a consistent methodology developed in previous works. In-cylinder insulation was added to each of the engines to evaluate the effects on performance. The goals of this simulation were to utilize energy that otherwise would be bypassed around the turbine

This paper summarizes the validation of a modified multi-step phenomenological soot model and an enhanced combustion model used for direct-injection natural gas engines. In this study, a modified phenomenological soot model including the key steps for soot formation, such as particle inception and surface growth, was developed in KIVA-3V to replace the empirical model for use in a glow plug assisted

Cylinder wall heat insulation using thermal barrier coatings is both an old and new thermal efficiency improvement technology for internal combustion engines. This review first outlines the history of thermal barrier coating (TBC) technologies applied to reciprocating engines from the 1970s up to the present day, by referring to several distinctive reference papers. These research efforts, however

To ensure that private cars can continue to be used in the future, they must become significantly more efficient and at the same time emit considerably less pollutants. In addition to pure electric drives, further optimized gasoline engines in hybrid powertrain configurations still offer major potentials in this respect. A major step toward increasing efficiency can be achieved by extremely lean burn

To explore a suitable combustion strategy for natural gas engines using jet ignition, lean burn with air dilution, stoichiometric burn with EGR dilution and lean burn with EGR dilution were investigated in a single-cylinder natural gas engine, and the performances of two kinds of jet ignition technology, passive jet ignition (PJI) and active jet ignition (AJI), were compared. In the study of lean burn

Machine learning (ML) models based on a large data set of in-cylinder flow fields of an IC engine obtained by high-speed particle image velocimetry allow the identification of relevant flow structures underlying cycle-to-cycle variations of engine performance. To this end, deep feature learning is employed to train ML models that predict cycles of high and low in-cylinder maximum pressure. Deep convolutional

This work reports on the derivation of simplified but accurate models to describe gas flow through a bore-piston ring contact in reciprocating machines like compressors or IC engines. On the basis of the aperture field of a contact deduced from real measurements carried out on an expanding ring in a bore, a scale analysis on the complete compressible flow model is performed, assuming ideal gas law

EGR cylinder-to-cylinder dispersion poses an important issue for piston engines, since it increases NOx and particulate matter (PM) emissions. In this work, the EGR distribution on a 6-cylinder intake manifold is analyzed by means of experiments, 0D/1D engine modeling and 3D CFD simulations at three different working points. Using a comprehensive set of measurements, statistical regressions for NOx

A new optical diagnostic technique for burned gas temperature measurements was introduced using visible thermally-excited fluorescence of strontium monohydroxide (SrOH). The technique is a significant improvement over previously developed alkali metal-based techniques in that it requires only one tracer substance, strontium acetylacetonate in ethanol, compared to two or three alkali metal precursors

Diesel engines continue to be used in truck applications, so reducing fuel use and hence CO2 emissions, is a priority. Single-stage turbocharged diesel engines are known to be fuel efficient under steady load at low speeds. However, the engine’s ability to track load transients becomes limited by emission constraints due to the rate of production values for smoke and the resulting higher nitrogen oxides

This work presents the development of a model to capture the NOx sensors cross sensitivity behavior based on NOx sensor cell temperature, as well as a model do predict the slip of the NOx and NH3 after the SCR catalyst, as a way to reduce the error in the exhaust emissions estimation needed for feedback SCR control strategies. The emissions prediction model is based on the different cross sensitivity

An experimental investigation was carried out to investigate Particulate Number (PN) emissions from a modern, small-capacity Gasoline Direct Injection (GDI) engine. The first part of the study focused on improving measurement repeatability using the Cambustion DMS-500 device. Results showed that sampling near the exhaust valve – while dampening the pressure oscillations in the sampling line – can significantly

Homogenous charge compression ignition (HCCI) combustion is a low temperature combustion process which combines high combustion efficiency with ultra-low NOx raw emissions. Steep increases of the in-cylinder pressure and unstable combustion sequences at the limits of the operating range can damage the engine and limit the use of HCCI to part load operation. This can be done using closed loop combustion

A flame front is quenched when approaching a cold wall due to excessive heat loss. Accurate computation of combustion rate in such situations requires accounting for near wall flame quenching. Combustion models, developed without considering wall effects, cannot be used for wall bounded combustion modelling, as it leads to wall flame acceleration problem. In this work, a new model was developed to

Unevaporated fuel films forming on the fuel injector tip of gasoline direct-injection engines burn in a diffusion flame at the time of spark, producing particulates and at some operating conditions, these films have been identified as the dominating source of particulate emissions. This work developed an analytical model for liquid film evaporation on the injector tip, that is, injector tip drying

The need for advanced combustion technologies for use in future highly efficient powertrains in the automotive sector is well understood. Pre-chamber combustors, a technology with numerous historic examples, are fast becoming a major area of research once again. Pre-chambers are proportionally small partially enclosed chambers where combustion of a small quantity of fuel and air initiates before transferring

Knock is the most crucial limitation in attaining the peak load required at high efficiency in heavy duty (HD) spark ignition (SI) engines. Renewable fuels such as ethanol and methanol have high resistance to autoignition and can help overcome this limitation. To reduce knock and improve efficiency further, dilution can be used to add specific heat capacity and reduce combustion temperature. This work

This paper aims at taking into account the chemistry of O3 in a 3D CFD simulation of compression ignition engine with Diesel type combustion for low load operating points. The methodology developed in this work includes 0D homogeneous reactors simulations, 3D RANS simulations and validation regarding experimental results. The 0D simulations were needed to take into account O3 reactions during the compression

The use of biofuels to replace fossil fuels as well as more stringent emission regulations for internal combustion engines cause a challenge for the engine manufacturers to build engines that can cope with a wide range of fuels, but still offer low exhaust emissions with no detriment to performance. In this work a test bed with a compression ignition engine has been used to measure emissions when using