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Spray-guided gasoline direct injection demonstrates great potential to reduce both fuel consumption and pollutant emissions. However, conventional materials used in high-pressure pumps wear severely under fuel injection pressures above 20 MPa as the lubricity and viscosity of gasoline are very low. The use of ceramic components promises to overcome these difficulties and to exploit the full benefits of spray-guided GDI-engines. As part of the Collaborative Research Centre “High performance sliding and friction systems based on advanced ceramics” at Karlsruhe Institute of Technology, a single-piston high-pressure gasoline pump operating at up to 50 MPa has been designed. It consists of 2 fuel-lubricated sliding systems (piston/cylinder and cam/sliding shoe) that are built with ceramic parts. The pump is equipped with force, pressure and temperature sensors in order to assess the behaviour of several material pairs.

The most significant operation limit prohibiting the further reduction of the CO2 emissions of gasoline engines is the occurrence of knock. Thus, being able to predict the incidence of this phenomenon is of vital importance for the engine process simulation - a tool widely used in the engine development. Common knock models in the 0D/1D simulation are based on the calculation of a pre-reaction state of the unburnt mixture (also called knock integral), which is a simplified approach for modeling the progress of the chemical reactions in the end gas where knock occurs. Simulations of thousands of knocking single working cycles with a model representing the Entrainment model’s unburnt zone were performed using a detailed chemical reaction mechanism. The investigations showed that, at specific boundary conditions, the auto-ignition of the unburnt mixture resulting in knock happens in two stages.

Novel Combustion technologies and strategies show high potential in reducing the fuel consumption of gasoline spark ignition (SI) engines. In this paper, a comparison between various gasoline combustion concepts at two representative engine operating points is shown. Advantages of the combustion concepts are analyzed using thermodynamic split of losses method. In this paper, a tool for thermodynamic assessment (Split of Losses) of conventional and new operating strategies of SI engine and its derivatives is used. Technologies, like variable valve actuation and/or gasoline direct injection, allow new strategies to run the SI engine unthrottled with early inlet valve closing (SI-VVA) combined with high EGR, charge stratification (SI-STRAT) and controlled auto ignition (CAI), also known as gasoline homogeneous charge compression ignition (HCCI). These diverse combustion concepts show thermodynamic gains that stem from several, often different sources.

Driving fun - one of the major thrills expected by the buyers of high-performance cars - must be absolutely preserved despite all the measures required to further reduce the car's exhaust emissions and fuel consumption. Powerful engines with high BMEP levels require large unrestricted inlet and outlet valve diameters and lifts as well as a wide camshaft phasing range at least on the intake side. In terms of exhaust emissions and fuel economy such an engine layout is rather unfavourable. Its inherent drawbacks, however, can be compensated by providing for what might be called a “two-in-one” configuration which combines a low-emission concept including intake-valve lift shifting and exhaust-camshaft phasing with a high-performance-engine concept complete with a wide intake camshaft phasing range and large intake valve lifts and a Varioram intake system. With this basic layout, even high-performance sports cars are able of falling below the current ULEV limits.

The range of Robert Bosch in-line pumps is designed for engines with cylinder outputs of up to 200 kW. Within this family of pumps the MW pump is used in small IDI engines and medium-sized DI engines with cylinder outputs in the region of 30 kW. More stringent exhaust emission legislation and the need to ensure optimum fuel economy call for efficient fuel-injection systems for diesel engines. In both of its designs the new MW pump meets these more exacting requirements and forms the contribution of Robert Bosch GmbH toward developing advanced diesel engines.

The goal of reducing the impact of road transportation on the environment can be reached by different approaches. The use of non-fossil synthetic fuels from renewable energy sources in the entire fleet of internal combustion engine vehicles is only one promising pathway to minimize the vehicle’s carbon footprint during the use phase. The steadily tightening emissions legislation confront the developers of future combustion engines with major challenges: Historically, the chemical and physical improvement of the combustion process, tail pipe emissions reduction and the development of optimized after-treatment systems were linked to improvements in fuel quality. In order to further decrease exhaust gas emissions, the optimization of the chemical composition of renewable fuels are a basic requirement.

Investigations were performed, in which the emission behavior of renewable and conventional fuels of different composition and renewable fuel components was observed. The influence of the start of injection on the emissions at WOT was investigated. This shows how much wall and valve wetting as well as the available evaporation time affects the mixture formation of the different fuels. Further, the air fuel ratio in an operating point for catalytic converter heating, with medium engine temperatures, was varied. This shows the ability of evaporation of the fuels at engine warm-up conditions and sub-stochiometric λ-values. The studied fuels were four fuel mixtures of significantly different composition of which three were compliant with the European fuel standard EN 228. A RON 98 in-field fuel, a Euro 6 reference fuel, an Anti-Spark-Fouling (ASF) fuel (designed for minimum soot production) and a potentially completely renewable, thus CO2-neural, fuel, which is designed by Dr. Ing. h.c.

A previous study by the authors has shown an efficiency benefit of up to Δηi = 10 % for stratified operation of a high pressure natural gas direct injection (DI) spark ignition (SI) engine compared to the homogeneous stoichiometric operation with port fuel injection (PFI). While best efficiencies appeared at extremely lean operation at λ = 3.2, minimum HC emissions were found at λ = 2. The increasing HC emissions and narrow ignition time frames in the extremely lean stratified operation have given the need for a detailed analysis. To further investigate the mixture formation and flame propagation und these conditions, an optically accessible single-cylinder engine was used. The mixture formation and the flame luminosity have been investigated in two perpendicular planes inside the combustion chamber.

In marine or stationary engines, consistent engine performance must be guaranteed for long-haul operations. A dual-fuel combustion strategy was used to reduce the emissions of particulates and nitrogen oxides in marine engines. However, in this case, the combustion stability was highly affected by environmental factors. To ensure consistent engine performance, the in-cylinder pressure measured by piezoelectric pressure sensors is generally measured to analyze combustion characteristics. However, the vulnerability to thermal drift and breakage of sensors leads to additional maintenance costs. Therefore, an indirect measurement via a reconstruction model of the in-cylinder pressure from engine block vibrations was developed. The in-cylinder pressure variation is directly related to the block vibration; however, numerous noise sources exist (such as, valve impact, piston slap, and air flowage).

The reduction of nitrous oxides in the exhaust gases of internal combustion engines using a urea water solution is gaining more and more importance. While maintaining the future exhaust gas emission regulations, like the Euro 6 for passenger cars and the Euro 5 for commercial vehicles, urea dosing allows the engine management to be modified to improve fuel economy as well. The system manufacturer Robert Bosch has started early to develop the necessary dosing systems for the urea water solution. More than 300.000 Units have been delivered in 2007 for heavy duty applications. Typical dosing quantities for those systems are in the range of 0.01 l/h for passenger car systems and up to 10 l/h for commercial vehicles. During the first years of development and application of urea dosing systems, instantaneous flow measuring devices were used, which were not operating fully satisfactory.

Regulations around the globe are driving the adoption of alternative fuels and vehicles through the implementation of stricter standards aimed at reducing carbon footprint and criteria emissions such as nitrogen oxides (NOx), particulate matter (PM), and total hydrocarbon (THC) emissions. Low emission zones have been implemented across Europe which restrict access by some vehicles with the aim of improving the air quality. The Paris Agreement on climate change declared governments’ intentions to reduce greenhouse gas (GHG) emissions as outlined in each country’s nationally determined contribution. Providing affordable energy to support prosperity while reducing environmental impacts, including the risks of climate change, is the dual challenge for the energy and transport industries.

A gray-box optimization procedure based on evolutionary algorithms for the initial design of a suspension concept for four wheel independently driven and steered vehicles is developed. With the presented optimization method, the energy consumption together with state of the art knowledge about the parametrization and design of vehicle suspension systems leads to an optimization setup closely to real world requirements while the vehicle’s topology is exploited. To this, the modelling presented in [1] is considered as a geometric suspension model. Furthermore, to take advantage of the potential of such vehicles, an autonomous closed-loop setup with integrated motion control is utilized. During the optimization, the chassis parameters with the most impact on energy consumption and driving dynamics, namely camber, caster, scrub radius and the steering axis inclination (SAI) depending on a varying caster angle and SAI in relation to the steering angle, will be focused.

The stricter worldwide emission legislation and growing demands for lower fuel consumption and CO2-emission require for significant efforts to improve combustion efficiency while satisfying the emission quality demands. Ethanol fuel combined with boosting on direct injection gasoline engines provides a particularly promising and, at the same time, a challenging approach. Brazil is one of the main Ethanol fuel markets with its E24 and E100 fuel availability, which covers a large volume of the national needs. Additionally, worldwide Ethanol availability is becoming more and more important, e.g., in North America and Europe. Considering the future flex-fuel engine market with growing potentials identified on downsized spark ignition engines, it becomes necessary to investigate the synergies and challenges of Ethanol boosted operation. Main topic of the present work focuses on the operation of Ethanol blends up to E100 at high loads up to 30 bar imep.

The impact of N-Methyl Aniline (NMA) octane booster on lubricating oil has previously been studied and the main findings were reported in SAE paper 2016-01-2273. Increased sludge formation had been observed in modified ACEA black sludge testing when NMA was added to the fuel but there was very limited viscosity increase, which did not corroborate the trend evidenced on modified CEC L-109 oxidation testing where significant viscosity increase was noted when NMA was added to the oil and fuel mixture. Accordingly, modified black sludge tests have been run with and without NMA added to the oil sump at the beginning of the test to better match modified L-109 oxidation bench test conditions. Results showed the same trend in terms of viscosity increase between the modified L-109 oxidation bench test and black sludge test.

The scope of this work is to propose a methodology to define multicomponent surrogate mixtures which describe the main evaporation characteristics of real gasoline fuels. Since real fuels are commonly complex mixtures with hundreds or thousands of hydrocarbons, their exact composition is generally not known. Only global characteristics are standardized. An accurate modeling of such complex mixtures in 3D-CFD requires the definition of a suitable surrogate. So far, surrogate mixtures have mostly been defined based on their combustion properties, such as ignition delay or burning velocity, irrespective of their evaporation characteristics. For this reason, in this work, a systematic study is carried out to develop a methodology to define mixtures of representative components that mimic the evaporation behavior of real fuels.

Fuel economy of two-wheelers is an important factor influencing the purchasing psychology of the consumer within the emerging markets. Additionally, air pollution being a major environmental topic, there is a rising concern about vehicle emissions, especially in the big cities and their metropolitan areas. Potentially, the relatively expensive engine management systems are providing more features and value in comparison to the carburettor counterpart. The combustion system analysis is carried out on a 125 cm3 motorcycle engine and the subsequent numerical simulation comparing the carburettor and the Electronic (Port) Fuel Injection which provides a basis to establish the fuel consumption benefit for the electronic injection systems [1].

Two-dimensional Mie and LIEF techniques were applied to investigate the spray formation of a high pressure gasoline swirl injector in a constant volume chamber. The results obtained provide information on the propagation of liquid fuel and fuel vapor for different fuel pressures and ambient conditions. Spray parameters like tip penetration, cone angles and two new defined parameters describing the radial fuel distribution were used to quantify the fuel distributions measured. Simultaneous detection of liquid and vapor fuel was applied to study the influence of ambient temperature, injector temperature and ambient pressure on the evaporating spray.

In this work a detailed soot model based on stationary flamelets is used to simulate soot emissions of a reactive Diesel spray. In order to represent soot formation and oxidation processes properly, a calibration of the soot reaction rates has to be performed. This model calibration is usually performed on basis of engine out soot measurements. Contrary to this, in this work the soot model is calibrated on local soot concentrations along the spray axis obtained from laser extinction chamber measurements. The measurements are performed with B7 certification Diesel and a series production multihole injector to obtain engine similar boundary conditions. In order to ensure that the flow and mixture field is captured well by the CFD-simulation, the simulated liquid penetration lengths and flame lift-off lengths are compared to chamber measurements.

The electrification of off-highway machines are increasing significantly. Advanced functionalities, beneficial energy efficiency and effectiveness are only a few advantages of electric propulsion systems. To control these complex systems in varying environments intelligent algorithms at system level are needed. This paper addresses the topic of machine learning algorithms applied to off-highway machines and presents a methodology based on artificial neural networks to identify and recognize recurrent load cycles and work tasks. To gain efficiency and effectiveness benefits the recognized pattern settings are applied to the electric propulsion system to adjust relevant parameters online. A dynamic adaption of the DC-link voltage based on the operating points of the machine processes is identified as such a parameter.

Increasing injection pressures together with Diesel fuel lubricated Common Rail pumps replacing oil lubricated systems demand a more sophisticated investigation of robustness and durability against particle contamination of fuel. The established way of requiring filtration efficiency levels per lab standard is not significant enough if we look at variable factors like vibration of the fuel filter and viscosity of the fuel. Because these and other factors tremendously influence filtration efficiency, future Diesel FIE cleanliness requirements will need to define an allowable contamination limit downstream of the filter. More precisely, this is not a scalar limit but a contamination collective that considers the varying vehicle filtration and operating environment. This paper describes a procedure for defining allowable contamination limits of the FIE components. The procedure includes sensitivity, robustness and “key life” tests.