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ELEVATE (European Low Emission V4 Automotive Two-stroke Engine) was a research project part funded by the European Commission to design and develop a compact and efficient gasoline two-stroke automotive engine. ...ELEVATE (European Low Emission V4 Automotive Two-stroke Engine) was a research project part funded by the European Commission to design and develop a compact and efficient gasoline two-stroke automotive engine. Five partners were involved in the project, IFP (Institut Français Du Pétrole) who were the project leaders, Lotus, Opcon (Autorotor and SEM), Politecnico di Milano and Queen's University Belfast. ...This paper describes the design philosophy of the engine as well as the application of the various partner technologies used. Incorporated in the design was an air assisted direct fuel injection system, IAPAC, (Injection Assistée Par Air Comprimé) and a charge trapping valve system in the exhaust port.

The influence of the inertia properties (mass, centre of gravity location, and inertia tensor) on the dynamic behaviour of the engine-gearbox system of a car is studied in this paper, devoting particular attention to drivability and comfort. The vibration amplitudes and the natural frequencies of the engine-gearbox system have been considered. Additionally, the loads transmitted to the car body have been taken into account. Both the experimental and the theoretical simulations confirmed that the engine-gearbox vibrations in the range 10 - 15 Hz are particularly sensitive to slight variation of the inertia properties. The effects on engine-gearbox vibrations due to half-axles, exhaust system, pipes and inner engine-gearbox fluids have been highlighted.

The present work is focused on the improvement of the turbulence sub-model, originally conceived to describe turbulence evolution in tumble-promoting engines. The turbulence model is here developed with reference to a SI heavy-duty CNG engine derived from a diesel engine. ...In the recent years, the interest in heavy-duty engines fueled with Compressed Natural Gas (CNG) is increasing due to the necessity to comply with the stringent CO2 limitation imposed by national and international regulations. ...To drive the engine development and reduce the time-to-market, the employment of numerical analysis is mandatory.

Predictive combustion models are useful tools towards the development of clean and efficient engines operating with alternative fuels. This work intends to validate two different combustion models on compression-ignition engines fueled with Dimethyl Ether. ...This work intends to validate two different combustion models on compression-ignition engines fueled with Dimethyl Ether. Both approaches give a detailed characterization of the combustion kinetics, but they substantially differ in how the interaction between fluid-dynamics and chemistry is treated. ...An experimental campaign was carried out on a heavy-duty truck engine running on DME at a constant load considering trade-off of EGR and SOI. Simulations results of 10 operating conditions show that both models can be successfully employed to predict cylinder pressure, heat release rate and pollutant emissions.

The aim of this study is to present briefly the reliability of the updated POLIMI mechanism for heavier alcohols and to investigate the fundamental role of chemical kinetics on the performance maps of HCCI engines fueled with n-butanol and n-pentanol, in terms of operability limits and engine efficiency. ...Heavier alcohols such as n-butanol and n-pentanol present ignition characteristic of interest for application in HCCI engines, due to the presence of the hydroxyl moiety reducing their low temperature reactivity compared to the parent linear alkanes (i.e. higher octane number). ...The promising performances of ethanol in a HCCI engine have been recently discussed by Bissoli et al. (Energy & Fuels, 2017, Submitted), observing wider stable operability conditions in terms of fuel/air load (λ) and exhaust gas recirculation (EGR) extent compared to PRF80 and PRF100.

Based on these specifications, a representative single cylinder research and development engine has been designed and manufactured. Detailed results of this experimental engine are presented in this new paper. ...The purpose of the ELEVATE (European Low Emission V4 Automotive Two-stroke Engine) industrial research project is to develop a small, compact, light weight, high torque and highly efficient clean gasoline 2-stroke engine of 120 kW which could industrially replace the relatively big existing automotive spark ignition or diesel 4-stroke engine used in the top of the mid size or in the large size vehicles, including the minivan vehicles used for multi people and family transportation. ...The purpose of the ELEVATE (European Low Emission V4 Automotive Two-stroke Engine) industrial research project is to develop a small, compact, light weight, high torque and highly efficient clean gasoline 2-stroke engine of 120 kW which could industrially replace the relatively big existing automotive spark ignition or diesel 4-stroke engine used in the top of the mid size or in the large size vehicles, including the minivan vehicles used for multi people and family transportation.

The demand of game-changing technologies to improve efficiency and abate emissions of heavy-duty trucks and off-road vehicles promoted the development of novel engine concepts. The Recuperated Split-Cycle (R-SC) engine allows to recover the exhaust gases energy into the air intake by separating the compression and combustion stages into two different but connected cylinders: the compressor and expander, respectively. ...The result is a potential increase of the engine thermal efficiency. Accordingly, the 3D-computational fluid dynamics (CFD) modelling of the gas exchange process and the combustion evolution inside the expander becomes essential to control and optimize the R-SC engine concept. ...Accordingly, the 3D-computational fluid dynamics (CFD) modelling of the gas exchange process and the combustion evolution inside the expander becomes essential to control and optimize the R-SC engine concept. This work aims to address the most challenging numerical aspects encountered in a 3D numerical simulation of an R-SC engine.

In this work a 1D model will be applied to the modeling of a V8 engine fueled with DI of hydrogen. The engine has been derived by a gasoline configuration and adapted to hydrogen in such a way to keep the same performance. ...Hydrogen engines are currently considered as a viable solution to preserve the internal combustion engine as a power unit for vehicle propulsion. ...In particular, lean-burn gasoline Spark-Ignition (SI) engines have been a major subject of investigations due to the reduced emission levels and high thermodynamic efficiency.

In this work an integration between a 1D code (Gasdyn) with a CFD code (OpenFOAM®) has been applied to improve the performance of a Moto3TM engine. The four-stroke, single cylinder S.I. engine was modeled, in order to predict the wave motion in the intake and exhaust systems and study how it affects the cylinder gas exchange process. ...The four-stroke, single cylinder S.I. engine was modeled, in order to predict the wave motion in the intake and exhaust systems and study how it affects the cylinder gas exchange process. The engine considered was characterized by having an air induction system with integrated filter cartridge, air-box and intake runner, resulting in a complex air-path form the intake mouth to the intake valves, which presents critical aspects when a 1D modeling is addressed. ...Predicted 1D and 1D-3D results, concerning pressure pulses in the intake system and volumetric efficiency, were used to guide the design stage in order to improve the engine performances in terms of torque and power output. Calculation carried out on prototyped geometries have been successfully compared to experimental measurements.

These simulations often describe the engine with a limited engine geometry neglecting the inlet and exhaust duct. This gives rise to the need to assume certain starting conditions such as the turbulence coming from the intake valve and the homogeneity of the air/fuel mixture entering the combustion chamber. ...Specifically, a dual-fuel marine engine running on methanol/diesel and natural gas/diesel fueling conditions is investigated. Dual-fuel engines can provide a short-term solution to cope with the more stringent emission legislations in the maritime sector. ...Dual-fuel engines can provide a short-term solution to cope with the more stringent emission legislations in the maritime sector.

The evolution of automotive engines calls for the design of electronic control systems optimizing the engine performance in terms of reduced fuel consumption and pollutant emissions. ...To this regard, the availability of reliable dynamic engine models plays an important role in the design of engine control and diagnostic systems, allowing for a significant reduction of the development times and costs. ...This paper presents a control-oriented model of the air-path system of today's gasoline internal combustion engines. The engine model is developed according to a Mean Value Model (MVM) approach, and includes the modeling of exhaust gas recirculation (EGR), valve variable timing (VVT) and tumble valves.

A current-production 1.3-liter, four-cylinder engine is selected, and available experimental test data are used for validation of the engine model. ...EA promoted combustion is considered as one of the most interesting technologies to improve the performance in diesel engines and to simultaneously control and reduce pollution. This paper explores, by means of 3-dimensional computational fluid dynamics simulations, the effects of EA on the performance and exhaust emissions of a high-speed direct-injection diesel engine. ...This paper explores, by means of 3-dimensional computational fluid dynamics simulations, the effects of EA on the performance and exhaust emissions of a high-speed direct-injection diesel engine. For the analysis, a customized version of the KIVA 3 V code, including a detailed combustion chemistry approach, coupled with a comprehensive oxidation mechanism as a diesel oil surrogate, is used.

The reliable prediction of pollutant emissions generated by IC engine powertrains during the WLTP driving cycle is a key aspect to test and optimize different configurations, in order to respect the stringent emission limits. ...This work describes the application of an integrated modeling tool in a co-simulation environment, coupling a 1D fluid dynamic code for engine simulation with a specific numerical code for aftertreatment modelling by means of a robust numerical approach, to achieve a complete methodology for detailed simulations of driving cycles. ...This co-simulation environment has been validated against the measured dataset of an SI, natural gas engine which was instrumented and tested at EMPA labs.

This paper describes the development, application and comparison of two different non-linear numerical codes, respectively based on a 1D and 3D schematization of the geometrical domain, for the prediction of the acoustic behavior of common silencing devices for i.c. engine pulse noise abatement. A white noise approach has been adopted and applied to predict the attenuation curves of silencers in the frequency domain, while a non-reflecting boundary condition was used to represent an anechoic termination. ...Finally, a hybrid approach, in which the CFD code has been integrated with the 1D model, is described and applied to the simulation of a single cylinder engine. The computed results are compared to the measured pressure waves and emitted sound pressure level spectra.

In this paper, computation fluid dynamics (CFD) simulations are performed to describe the effect of in-cylinder flow structures on the formation and oxidation of soot in a swirl-supported light-duty diesel engine. The focus of the paper is on the effect of swirl motion and injection pressure on late cycle soot oxidation. ...In this work, Representative Interactive Flamelets (RIF) method is employed to describe the chemical reactions, ignition, flame propagation and emissions in the engine. The CFD simulations are validated using experimental measurement of light-duty diesel engine at two different loads. ...The CFD simulations are validated using experimental measurement of light-duty diesel engine at two different loads. A good agreement is achieved between the model results and the pressure, heat release rates and emissions from the experiment.

In this work, the combustion characteristics of an active pre-chamber system are experimentally investigated using a single-cylinder research engine. The engine under exam is a large bore heavy-duty unit with an active pre-chamber fuelled with compressed natural gas. ...Nowadays, NOx emissions standards are stringent for spark-ignition (SI) internal combustion engines (ICEs) and many techniques are investigated to limit these emissions. Among these, an extremely lean combustion has a large potential to simultaneously reduce the NOx raw emissions and the fuel consumption of SI ICEs. ...Among these, an extremely lean combustion has a large potential to simultaneously reduce the NOx raw emissions and the fuel consumption of SI ICEs. Engines with pre-chamber ignition system are promising solutions for realizing a high air-fuel ratio which is both ignitable and with an adequate combustion speed.

Increasing demands on the capabilities of engine simulation and the ability to accurately predict both performance and acoustics has lead to the development of several numerical tools to help engine manufacturers during the prototyping stage. ...Increasing demands on the capabilities of engine simulation and the ability to accurately predict both performance and acoustics has lead to the development of several numerical tools to help engine manufacturers during the prototyping stage. The aid of CFD tools (3D and 1D) can remarkably reduce the duration and the costs of this stage. ...This is designed to model the acoustics and the fluid dynamics of both intake and exhaust system components used in internal combustion engines. Models of components are built using a network of quasi-3D cells based primarily on the geometry of the system.

The scope of the work presented in this paper was to apply the latest open source CFD achievements to design a state of the art, direct-injection (DI), heavy-duty, natural gas-fueled engine. Within this context, an initial steady-state analysis of the in-cylinder flow was performed by simulating three different intake ducts geometries, each one with seven different valve lift values, chosen according to an estabilished methodology proposed by AVL. ...Subsequently, full-cycle, cold-flow simulations were performed for three different engine operating points, in order to evaluate the in-cylinder development of TR and turbulent kinetic energy (TKE) under transient conditions. ...Three specific engine operating points were simulated and different combinations of turbochargers and valve lift laws were tested.

Direct-injection technology represents today a very interesting solution to the typical problems that are generally encountered in SI, gas-fueled engines such as reduced volumetric efficiency, backfire and knock. However, development of suitable injection systems and combustion chamber geometry is necessary to optimize the fuel-air mixing and combustion processes. ...In this work, a numerical methodology for the simulation of the gas exchange and injection processes in gas-fueled engines was developed within the Lib-ICE framework, which is a set of libraries and applications for IC engine modeling developed using the OpenFOAM® technology. ...In this work, a numerical methodology for the simulation of the gas exchange and injection processes in gas-fueled engines was developed within the Lib-ICE framework, which is a set of libraries and applications for IC engine modeling developed using the OpenFOAM® technology. The gas exchange and fuel injection processes were simulated into a four-valve, pent-roof hydrogen-fueled engine with optical access.

Among the different possible technological solutions, this paper focuses on the evaluation of the potential of a burner system, which is activated before the engine start. The hypothetical burner exploits the lean combustion of an air-gasoline mixture to generate a high temperature gas stream which is directed to the catalyst section promoting a fast heating of the substrate. ...Moreover, a CFD model has been developed to investigate the light-off of the reactions during the initial operation of the burner and the subsequent start of the engine. The model, developed on the basis of the OpenFOAM code, resorts to a multi-region approach, where different meshes are employed to describe the fluid domain and the solid regions, namely the catalytic porous substrates and the metallic walls constituting pipes and canning. ...The methodology has been then applied to the preliminary analysis of the catalyst light-off at engine cold start, considering a full exhaust line equipped with burner-like system.