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The Methane Fuel Based Turbocharged Direct Injection Engine in a Hybrid Powertrain - An Efficient Synergy

Continental Powertrain-Friedrich Graf, Stefan Lauer, Jan Ehrhard
Ford-Werke GmbH-Harald Stoffels, Carsten Weber
Published 2019-09-09 by SAE International in United States
There is no doubt that the modern internal combustion engine (ICE) is approaching its theoretical limits in terms of efficiency. Owed to the fact that the conversion of fuel-bound chemical energy into effectively usable power by combustion is largely defined by the fuel properties, the combustion process and the implicit phenomenon of abnormal combustion is a governing factor that limits further efficiency increases.However, the use of a knock-resistant fuel such as methane is leading to a significant raise in the average combustion pressure and total engine efficiency. In turn this requires a base engine architecture that is specially designed to cater the increased thermal and mechanical requirements so that the positive fuel properties can be fully exploited.Furthermore, an improvement of the energy balance is achieved by utilizing the kinetic energy stored in the vehicle by means of electrical recovery. In consequence, a positive synergy can be observed when mating this type of internal combustion engine to a hybrid powertrain. This hybrid powertrain consists of a P2 hybrid module containing an offset 48V electrical machine and…
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Hybrid Powertrain Technology Assessment through an Integrated Simulation Approach

Continental-Naroa Zaldua-Moreno, Lorenzo Pace
Ford Werke GmbH-Harald Stoffels
Published 2019-09-09 by SAE International in United States
Global automotive fuel economy and emissions pressures mean that 48 V hybridisation will become a significant presence in the passenger car market. The complexity of powertrain solutions is increasing in order to further improve fuel economy for hybrid vehicles and maintain robust emissions performance. However, this results in complex interactions between technologies which are difficult to identify through traditional development approaches, resulting in sub-optimal solutions for either vehicle attributes or cost. The results presented in this paper are from a simulation programme focussed on the optimisation of various advanced powertrain technologies on 48 V hybrid vehicle platforms. The technologies assessed include an electrically heated catalyst, an insulated turbocharger, an electric water pump and a thermal management module. The novel simulation approach undertaken uses an integrated toolchain capturing thermal, electrical and mechanical energy usage across all powertrain sub-systems. Through integrating 0-D and 1-D sub-models into a single modelling environment, the operating strategy of the technologies can be optimised while capturing the synergies that exist between them. This approach enables improved and more informed cost/benefit ratios for…
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Optimal Engine Re-Start Strategy on a Mild Hybrid Powertrain by Means of Up-Front Modelling

Ford Werke GmbH-Harald Stoffels, Shan-An Kao, Michael Frenken
Published 2019-09-09 by SAE International in United States
The ability to switch off the internal combustion engine (ICE) during vehicle operation is a key functionality in hybrid powertrains to achieve low fuel economy. However, this can affect driveability, namely acceleration response when an ICE re-engagement due to a driver initiated torque demand is required. The ICE re-start as well as the speed and load synchronisation with the driveline and corresponding vehicle speed can lead to high response times. To avoid this issue, the operational range where the ICE can be switched off is often compromised, in turn sacrificing fuel economy. Based on a 48V off-axis P2 hybrid powertrain comprising a lay-shaft transmission we present an up-front simulation methodology that considers the relevant parameters of the ICE like air-path, turbocharger, friction, as well as the relevant mechanical and electrical parameters on the hybrid drive side, including a simplified multi-body approach to reflect the relevant vehicle and powertrain dynamics. Applying different ICE re-start strategies at different speeds and gears, the driveability of the ICE re-engagement was evaluated using a commercialized driveability evaluation tool. Subjective ratings,…
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In-Situ Measurements of the Piston and Connecting Rod Dynamics Correlated with TEHL-Simulation Techniques

SAE International Journal of Engines

Ford Werke GmbH-Harald Stoffels
IVK/Universitat Stuttgart-Wolfgang Gross
  • Journal Article
  • 2017-24-0157
Published 2017-09-04 by SAE International in United States
High combustion pressure in combination with high pressure gradient, as they e.g. can be evoked by high efficient combustion systems and e.g. by alternative fuels, acts as broadband excitation force which stimulates natural vibrations of piston, connecting rod and crankshaft during engine operation. Starting from the combustion chamber the assembly of piston, connecting rod and crankshaft and the main bearings represent the system of internal vibration transfer. To generate exact input and validation values for simulation models of structural dynamic and elasto-hydrodynamic coupled multi-body systems, experimental investigations are done. These are carried out on a 1.5-l inline four cylinder Euro 6 Diesel engine. The modal behaviour of the system was examined in detail in simulation and test as a basis for the investigations.In an anechoic test bench airborne and structure-borne noises and combustion pressure are measured to identify the engine´s vibrational behaviour. To understand the behaviour of the connecting rod as the key component in more detail its elongation, using semiconductor strain gauges at the connecting rod shank and a linkage system, is also measured.…
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Potential of Electric Energy Recuperation by Means of the Turbocharger on a Downsized Gasoline Engine

Ford Werke GmbH-Harald Stoffels, Jens Dunstheimer, Christian Hofmann
Published 2017-09-04 by SAE International in United States
The application of a turbocharger, having an electric motor/generator on the rotor was studied focusing on the electric energy recuperation on a downsized gasoline internal combustion engine (turbocharged, direct injection) using 1D-calculation approaches. Using state-of-the art optimization techniques, the settings of the valve timing was optimized to cater for a targeted pre-turbine pressure and certain level of residual gases in the combustion chamber to avoid abnormal combustion events. Subsequently, a steady-state map of the potential of electric energy recuperation was performed while considering in parallel different efficiency maps of the potential generator and a certain waste-gate actuation strategy. Moreover, the results were taken as input to a WLTP cycle simulation in order to identify any synergies with regard to fuel economy. Finally, the value of electric energy, either recuperated via the electric turbocharger, inputting the electric conversion efficiency as a function of the rotor speed of the turbocharger based on measured characteristics, was put in comparison to the same amount of electric energy, supplied by the conventional generator in the front-end accessory drive. The study…
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Powertrain Architecture affects Driving Habits

SAE International Journal of Engines

Ford Werke GmbH-Harald Stoffels, Kay Hohenboeken
  • Journal Article
  • 2014-01-2869
Published 2014-10-13 by SAE International in United States
The impact of the number of cylinders on two downsized gasoline engines on driving habits in the same passenger-vehicle type was investigated. This was carried out with two similar vehicles, equipped with an in-line three cylinder (i3) and an in-line four cylinder (i4) engine, both having same power, torque and transient-response behaviour. Both engine types were mated to six-speed manual transmissions with same gear-ratios and dual-mass flywheel characteristics. The study was performed by letting a statistically significant number of subjects driving the same route and both vehicles consecutively. The relevant data during driving were recorded simultaneously from either vehicle integrated sensors (CAN), and secondary transducers.We found that the in-line three cylinder was operated at higher engine speeds even though it was operated at similar acceleration- and load levels like the in-line four cylinder power-train, whereat the off-set of the engine speed shows no correlation with the difference in firing frequency between both engine types. Furthermore, it was revealed that the i3-engine faced gear-up-shift events at higher engine speeds than the i4-engine. Interestingly, the up-shift speeds…
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An Approach for the Objective Description of Vehicle Longitudinal Acceleration

Ford Werke GmbH-Harald Stoffels
Published 2011-09-11 by SAE International in United States
A trend in vehicle propulsion of converting from power sources such as a naturally aspirated internal combustion engine to turbocharged engines (Downsizing), multi-mode combustion systems (stratified charged combustion, HCCI) or multi-power source propulsion systems such as hybrid power-trains, can be observed. The subsequent switching between these different combustion modes or power sources, and, more importantly, the incorporation of turbochargers (turbo-lag) can affect the driveability, i.e. the smoothness of torque provision during transient driving manoeuvres. So far there is a lack of methodologies that can quantify and objectively describe vehicle transient acceleration events from a driver's point of perception. Thus an approach was developed while incorporating the acceleration transducers of men, the vestibular apparatus, into a longitudinal vehicle model with a transient engine / powertrain model. Finally the interaction between boost pressure generation, generated torque, vehicle acceleration and resulting stimulus of the driver is derived. In summary, this approach can support the development of well perceived longitudinal acceleration of vehicles.
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Analysis of Transient Operation of Turbo Charged Engines

SAE International Journal of Engines

Ford Werke GmbH-Harald Stoffels, Stefan Quiring, Bert Pingen
  • Journal Article
  • 2010-32-0005
Published 2010-09-28 by SAE International in United States
Transient operation of turbocharged engines is mostly optimised in the light of quickness of response and the provision of the demanded torque. The time from demanded boosted torque to delivered torque above the maximum torque provided by the natural aspirated torque value is known as turbo-lag. This could reveal as an issue for small gasoline turbo-charged engines with a displacement of 1.0ltr or lower. These small types of engines are moving more and more in the focus for automobile applications. To provide the required power and torque, gasoline direct injection and turbo-charging are helpful in order to enable a reduction of fuel consumption by both de-throttled operation over a large area of operation and improved thermal efficiency among others achieved by maintaining an appropriate compression ratio. However, the application of a turbocharger especially on small engines drives also the back-pressure at the exhaust, in turn affecting the knock sensitivity of the combustion and thus impacting efficiency and power negatively. To achieve low levels of back-pressure even on small engines, the size of the turbocharger is…
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Combustion Noise Investigation on a Turbocharged Spray Guided Gasoline Direct Injection I4-Engine

Ford Werke GmbH-Harald Stoffels
Published 2005-05-16 by SAE International in United States
Downsizing of Gasoline Direct Injection engines is a way to reduce greenhouse emissions. A downsized engine will have a much higher specific power density, caused by a significant higher brake mean effective pressure (BMEP). This higher BMEP can be enabled by a turbocharger in combination with gasoline direct injection. In addition, good efficiency is accompanied by fast combustion, i.e. a fast heat release rate. All these factors can lead to an increased level of combustion noise excitation, which means in turn a higher level of radiated noise. Thus a study on impact factors on the combustion noise excitation was carried out on a small I4-gasoline engine, having spray-guided direct injection, combined with a turbocharger. It was found that high intake tumble levels, which e.g. are caused by the intake port geometry or different actuation strategies of the swirl control device, can lead to an increased level of noise and roughness. The level of noise can be controlled by varying the spark angle. In addition, the impact of different fuel qualities were taken into account when…
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NVH Aspects of a Downsized Turbocharged Gasoline Powertrain with Direct Injection

Ford Werke AG-Harald Stoffels, Markus Schroeer
Published 2003-05-05 by SAE International in United States
The European Automotive Industry has committed to reduce the emissions. In order to comply with these CO2 requirements, the introduction of fuel efficient technologies is absolutely mandatory. Therefore ‘Downsizing’ is a known way to reduce part load fuel consumption by combining significant displacement reduction with turbocharging to achieve equivalent torque and power levels [1]. To fulfill these demands, an inline gasoline three cylinder powertrain with turbocharged direct injection (SCi Turbo) has been developed. The challenge during the development of such a powertrain is that no degradation on customer demands regarding the key criteria, among others driveability and NVH, is allowed.This paper will show the powertrain components that are affected most by these NVH attributes; this concerns mainly the engine and the power conversion system. The results, achieved by CAE and Measurements, show clearly that a potential deterioration of the different noise sources can be more than compensated by the introduction of certain countermeasures.
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