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This paper presents a concept of a high efficiency stoichiometric gasoline engine first published in [1]. The engine is modelled in GT-Power and uses the FKFS UserCylinder. ...The basic concept of the engine for the model was first published in [2] and [3] by Negüs et al. and includes engine friction reduction, improved turbocharger efficiency, variable compression ratio and variable valve train to allow Miller-Cycle and zero-cam profile cylinder deactivation capability. ...This slows down the pre-knock reactions and further reduces the engine's knock probability. The engine uses an electrically heated three-way catalytic converter and a gasoline particle filter.

Based on an 1D physical engine model of a turbo-charged direct injection gasoline engine with variable valve timing (VVT), a high-performance hybrid simulation model has been developed for increasing computing performance. ...A performance evaluation of the hybrid engine model shows that, the mean deviations of brake torque, MFB50 and NO emissions compared to the physics-based reference mode are respectively 0.529%, 0.048°CA and 32.67ppm over the whole engine characteristic map, indicating an equal calculation quality. ...A performance evaluation of the hybrid engine model shows that, the mean deviations of brake torque, MFB50 and NO emissions compared to the physics-based reference mode are respectively 0.529%, 0.048°CA and 32.67ppm over the whole engine characteristic map, indicating an equal calculation quality. While maintaining the calculation accuracy, the neural networks with FMU connections realize a combustion chamber calculation 5- to 10-fold faster than real-time and an acceleration of the whole engine calculation of up to 80% compared to the completely physics-based simulation.

The methodology is developed using a passenger car engine (Test Engine I) and validated on a large engine (Test Engine II). Whereas the passenger car engine has a water jacket with the cylinders in cross flow, the large engine has single cylinder cooling with flow along the cylinder axis. ...Whereas the passenger car engine has a water jacket with the cylinders in cross flow, the large engine has single cylinder cooling with flow along the cylinder axis. ...By using complex thermal management strategies, it is possible to make engine heat distribution more accurate and dynamic, thereby increasing efficiency. Significant efforts are made to improve the cooling efficiency of the engine water jacket by using 3D CFD.

It consists in operating the engine with a rich in-cylinder mixture and completing the oxidation of fuel inside the exhaust manifold. ...The following investigation focuses on the implementation of post-oxidation by means of scavenging in a four-cylinder, turbocharged, direct injection spark ignition engine. The investigation is based on detailed measurements that are carried out at the test-bench. ...At first a 3D-CFD full-engine model has been implemented to reproduce the complete engine from the air-box up to the turbine inlet. This model is able to simulate all the relevant full-engine effects like scavenging, cylinder-to-cylinder interaction and local inhomogeneity inside the cylinder.

The proposed paper deals with the development process and initial measurement results of an opposed-piston combustion engine for application in a Free-Piston Linear Generator (FPLG). The FPLG, which is being developed at the German Aerospace Center (DLR), is an innovative internal combustion engine for a fuel based electrical power supply. ...The FPLG, which is being developed at the German Aerospace Center (DLR), is an innovative internal combustion engine for a fuel based electrical power supply. With its arrangement, the pistons freely oscillate between the compression chamber of the combustion unit and a gas spring with no mechanical coupling like a crank shaft. ...The new engine is constructed on and implemented at a hydraulic free-piston test bench at DLR which controls the piston movements by two hydraulic actuators.

In the second analysis, the fuel investigation - conducted virtually at the FKFS of Stuttgart and experimentally at the engine laboratory of the Chair of Internal Combustion Engines at the Technical University of Munich with the support from Volkswagen Motorsport GmbH - on a single-cylinder research engine operating with the innovative SACI (Spark Assisted Compression Ignition) combustion concept is presented. ...This implies an increase in development complexity, which needs the support of engine simulations. In this work, the virtual modeling of real fuel behavior is addressed to improve current simulation capabilities in studying how a specific composition can affect the engine performance. ...In this work, the virtual modeling of real fuel behavior is addressed to improve current simulation capabilities in studying how a specific composition can affect the engine performance. The goal is to create a series of models that allow to virtually investigate different fuels and to minimize, as much as possible, the costly and time-consuming experimental tests.

At specific operating conditions, the auto-ignition in the unburnt mixture that precedes the occurrence of knock in conventional SI engines happens in two stages. In a previous publication, the authors demonstrated that the low-temperature heat release significantly influences the auto-ignition behavior of the mixture, thus severely impairing the prediction capabilities of the Livengood-Wu integral that the majority of the commonly used 0D/1D knock models are based on. ...Based on the proposed two-stage auto-ignition prediction approach, this paper presents a new knock model for the development of future SI engine concepts in a 0D/1D simulation environment. In addition to not considering low-temperature ignition, the commonly used knock models based on the Livengood-Wu integral assume that no knock can occur after a pre-defined, constant MFB-point. ...The evaluation of measured knocking single cycles however has revealed that the latest possible MFB-point where knock can occur changes significantly with parameters such as engine speed and EGR rate. Hence, a cycle-individual criterion for the occurrence of knock accounting for the current operating conditions is needed.

This shows the strong trend in the automotive industry away from conventional powertrains with internal combustion engines. The aim is to reduce the transport sector's contribution to CO2 emissions. However, it should be noted that this only applies when renewable energy is used. ...Moreover, a ban on combustion engines would lead to an additional increase in cumulative CO2 emissions. An important aspect on the way to sustainable mobility solutions is addressing the existing fleet. ...The approximately 1.25 billion vehicles predominantly powered by internal combustion engines can make a significant contribution to reduce greenhouse gas emissions by using renewable fuels.

Emission-simulation models are highly important in simulating CI engines. The nitrogen-oxide and soot emissions are simulated with a “combined” approach based on an inhomogeneous two-zone model.

This is especially true for turbocharged engines, as the coupling of the combustion engine and the turbocharger forms a complex system in which the components influence each other remarkably causing, for example, the well-known turbo lag. ...The simulation of transient engine behavior has gained importance mainly due to stringent emission limits, measured under real driving conditions and the concurrently demanded vehicle performance. ...Three-dimensional computational fluid dynamics (3D-CFD) simulations of full engines in stationary operating points have become practicable several years ago and will remain a valuable tool in virtual engine development; however, the next logical step is to extend this approach into the transient domain.

In the proposed EVD model each technical element (Engine, Vehicle) is distinct and can be interchangeable. For example, the engine can be virtually optimized and the influence of different technical configurations or engine mapping on the global performance can be investigated. ...In Motorsports the understanding of the real engine performance within a complete circuit lap is a crucial topic. On the basis of the telemetry data the engineers are able to monitor this performance and try to adapt the engine to the vehicle's and race track's characteristics and driver's needs. ...On the basis of the telemetry data the engineers are able to monitor this performance and try to adapt the engine to the vehicle's and race track's characteristics and driver's needs. However, quite often the telemetry is the sole analysis instrument for the Engine-Vehicle-Driver (EVD) system and it has no prediction capability.

Engine valve flow coefficients are used to describe the flow throughput performance of engine valve/port designs, and to model gas exchange in 0D/1D engine simulation. ...Besides this, the influence of flow pulsation on flow coefficients is investigated using pressure ratio profiles, which are derived from engine test bench measurements at different engine speeds. These profiles, one with, and one without change in flow direction, are applied to a 1D and a 3D CFD flow test bench model at various valve lifts. ...Engine valve flow coefficients are used to describe the flow throughput performance of engine valve/port designs, and to model gas exchange in 0D/1D engine simulation. Valve flow coefficients are normally determined at a stationary flow test bench, separately for intake and exhaust side, in the absence of the piston.

The development of future gasoline engines is dominated by the study of new technologies aimed at reducing the engine negative environmental impact and increase its thermal efficiency. ...One common trend is to develop smaller engines able to operate in stoichiometric conditions across the whole engine map for better efficiency, lower fuel consumption, and optimal conversion rate of the three-way catalyst (TWC). ...This work is part of the FVV project number 1367, “Water Injection in Spark-Ignition Engines II”, which investigates the coexistence of two different engine technologies that heads towards the same direction of sustainability of the internal combustion engine: water injection and eFuels.

Porsche AG and FKFS, already partners for the development of engines with eFuels, propose a new study carried out on a research engine, investigating the combination of Porsche synthetic gasoline (POSYN) with an engine with millerization and passive pre-chamber. ...The virtual development using different combination of fuels and hardware modifications led to a rise of engine indicated efficiency at high load from 39 % to 42 %, with constant engine compression ratio and stoichiometric combustion. ...The new CO2 and emissions limits imposed to European manufacturers require the adoption of different innovative solutions, such as the use of potentially CO2-neutral synthetic fuels alongside a tailored development of the internal combustion engine, as an excellent solution to accompany the hybridization of vehicles. Dr.Ing. h.c. F. Porsche AG and FKFS, already partners for the development of engines with eFuels, propose a new study carried out on a research engine, investigating the combination of Porsche synthetic gasoline (POSYN) with an engine with millerization and passive pre-chamber.

For long haul transport, diesel engine due to its low fuel consumption and low operating costs will remain dominant over a long term. ...However, the new fuel properties and the changed combustion characteristics place new demands on engine design. Meanwhile, the use of new fuels also creates new degrees of freedom to operate diesel engines. ...Meanwhile, the use of new fuels also creates new degrees of freedom to operate diesel engines. In this work, the application of dimethoxymethane (OME1) is investigated by means of 1D simulation at three operating points in a truck diesel engine.

Engine valve flow coefficients are not only used to characterize the performance of valve/port designs, but also for modelling gas exchange in 0D/1D engine simulation. ...Engine valve flow coefficients are not only used to characterize the performance of valve/port designs, but also for modelling gas exchange in 0D/1D engine simulation. Flow coefficients are usually estimated with small pressure ratios and at ambient air conditions. ...In contrast, the ranges for pressure ratio, pressure and temperature level during engine operation are much more extensive. In this work the influences of these three parameters on SI engine poppet valve flow coefficients are investigated using 3D CFD and measurements for validation.

The present paper summarizes the approach for a first demonstration of HCCI combustion using the high variability of the FPLG engine concept. 3D-CFD and chemical kinetics simulations of the in-cylinder processes are the basic steps towards the implementation of HCCI combustion in the FPLG engine. By means of these simulations new engine components and a HCCI specific operating strategy were developed. ...In this paper the development approach and the results of numerical and experimental investigations on homogeneous charge compression ignition in a free piston engine are presented. The Free Piston Linear Generator (FPLG) is a new type of internal combustion engine designed for the application in a hybrid electric vehicle. ...The Free Piston Linear Generator (FPLG) is a new type of internal combustion engine designed for the application in a hybrid electric vehicle. The highly integrated system consists of a two-stroke combustion unit, a linear generator, and a mass-variable gas spring.

Moreover, an optimized engine design suiting the advantages of natural gas in knock resistance and lean mixtures keeping in mind the challenges of power density, efficiency and cold start manoeuvres. ...In the public funded project MethMag (Methane lean combustion engine) a gasoline fired three-cylinder-engine is redesigned based on this change of requirements and benchmarked against the previous gasoline engine. ...In the public funded project MethMag (Methane lean combustion engine) a gasoline fired three-cylinder-engine is redesigned based on this change of requirements and benchmarked against the previous gasoline engine. A new combustion chamber design, including modified piston bowls for high compression ratio, a cylinder head with tumble intake ports, a direct gas injection and an active prechamber ignition system are the centrepieces of the new combustion system.

For this purpose a detailed 1D-CFD model within an HEV drivetrain is compared to a ‘traditional’ map-based combustion engine model as well as different types of simplified engine models which are able to reduce computing time significantly while keeping the model accuracy at a high level. ...The performance of said engine models is evaluated within a HEV drivetrain model. Results for the New European Driving Cycle as well as the Artemis Urban Driving Cycle are shown.

Due to increasingly strict emission regulations, lean combustion concept has become an essential direction of internal combustion engine development to reduce engine emissions. However, lean combustion will lead high combustion instability and unpredictive engine emissions. ...However, lean combustion will lead high combustion instability and unpredictive engine emissions. The combustion instability is represented as the high cycle-to-cycle variation. ...Therefore, understanding the mechanism of cycle-to-cycle variation is crucial for the internal combustion engine design. This paper investigates the cause-and-effect chain of cycle-to-cycle variation of spark ignition engines using 3D CFD simulations with CONVERGE v3.0.