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This work is a continuation of earlier results presented by the authors. In the current investigations the biofuels hydrogenated vegetable oil (HVO) and 1-octanol are investigated as pure components and compared to EN 590 Diesel. In a final step both biofuels are blended together in an appropriate ratio to tailor the fuels properties in order to obtain an optimal fuel for a clean combustion. The results of pure HVO indicate a significant reduction in CO-, HC- and combustion noise emissions at constant NOX levels. With regard to soot emissions, at higher part loads, the aromatic free, paraffinic composition of HVO showed a significant reduction compared to EN 590 petroleum Diesel fuel. But at lower loads the high cetane number leads to shorter ignition delays and therefore, ignition under richer conditions.

The residue and waste streams of existing industry offer feasible and sustainable raw materials for biofuel production. All kind of biomass contains carbon and hydrogen which can be turned into liquid form with suitable processes. Using hydrotreatment or Biomass-to-Liquid technologies (BTL) the liquid oil can be further converted into transportation biofuels. Hydrotreatment technology can be used to convert bio-oils and fats in to high quality diesel fuels that have superior fuel properties (e.g. low aromatic content and high cetane number) compared to regular diesel fuel and first generation ester-type diesel fuel. UPM has developed a new innovative technology based on hydrotreatment that can be used to convert Crude Tall Oil (CTO) into high quality renewable diesel fuel. This study concentrated on determining the functionality and possible effects of CTO based renewable diesel as a blending component on engine emissions and engine performance.

The current and future restrictions on pollutant emissions from internal combustion engines require a holistic investigation of the abilities of alternative fuels to optimize the combustion process and ensure cleaner combustion. In this regard, the Tailor-made Fuels from Biomass (TMFB) Cluster at Rheinisch-Westfälische Technische Hochschule (RWTH) Aachen University aims at designing production processes for biofuels as well as fuels optimal for use in internal combustion engines. The TMFB Cluster's scientific approach considers the molecular structure of the fuels as an additional degree of freedom for the optimization of both the production pathways and the combustion process of such novel biofuels. Thus, the model-based specification of target parameters is of the utmost importance to improve engine combustion performance and to send feedback information to the biofuel production process.

The present work is a continuation of the earlier published results by authors on the investigation of Hydrogenated Vegetable Oil (HVO) on a High Efficiency Diesel Combustion System (SAE Int. J. Fuels Lubr. Paper No. 2013-01-1677 and JSAE Paper No. 283-20145128). In order to further validate and interpret the previously published results of soot microstructure and its consequences on oxidation behavior, the test program was extended to analyze the impact of soot composition, optical properties, and physical properties such as size, concentration etc. on the oxidation behavior. The experiments were performed with pure HVO as well as with petroleum based diesel and today's biofuel (i.e. FAME) as baseline fuels. The soot samples for the different analyses were collected under constant engine operating conditions at indicated raw NOx emissions of Euro 6 level using closed loop combustion control methodology.

In recent years, more attention has been focused on environment pollution and energy source issues. As a result, increasingly stringent fuel consumption and emission legislations have been implemented all over the world. For automakers, enhancing engine’s efficiency as a must contributes to lower vehicle fuel consumption. To reach this goal, Geely auto started the development of a 3-cylinder 1.0L turbocharged direct injection (TGDI) gasoline engine to achieve a challenging fuel economy target while maintaining fun-to-drive and NVH performance. Demanding development targets for performance (specific torque 205Nm/L and specific power 100kW/L) and excellent part-load BSFC were defined, which lead to a major challenge for the design of the combustion system. Considering air/fuel mixture, fuel wall impingement and even future potential for lean burn combustion, a symmetrical layout and a central position for the injector with 200bar injection pressure was determined.

Improvements in the efficiency of internal combustion engines has led to a reduction in exhaust gas temperatures. The simultaneous tightening of exhaust emission limits requires ever more complex emission control methods, including aftertreatment whose efficiency is crucially dependent upon the exhaust gas temperature. Double-walled (also called air-gap) exhaust manifold and turbine housing modules made from sheet metal have been used in gasoline engines since 2009. They offer the potential in modern Diesel engines to reduce both the emissions of pollutants and fuel consumption. They also offer advantages in terms of component weight and surface temperatures in comparison to cast iron components. A detailed analysis was conducted to investigate the potential advantages of insulated exhaust systems for modern diesel engines equipped with DOC and SCR coated DPF (SDPF).

Modifications have been made to the calibration and control of Diesel engines to increase the temperature of the exhaust especially in cold weather and part load operation. The main purpose for this advanced calibration is to enable the reduction of emissions by improving catalytic activity. An alternative method for increasing exhaust temperature is providing electric heat. Test results show the feasibility of applying various amounts of electric heat and the related increases in exhaust temperature as well as speed of heating. Simulation modeling extends the application of electric heat to a complete engine map and explores the potential impact on engine performance and emission reduction benefits.

Gasoline Controlled Auto Ignition offers a high CO2 emission reduction potential, which is comparable to state-of-the-art, lean stratified operated gasoline engines. Contrary to the latter, GCAI low temperature combustion avoids NOX emissions, thereby trying to avoid extensive exhaust aftertreatment. The challenges remain in a restricted operation range due to combustion instabilities and a high sensitivity towards changing boundary conditions like ambient temperature, intake pressure or fuel properties. Once combustion shows instability, cyclic fluctuations are observed. These appear to have near-chaotic behavior but are characterized by a superposition of clearly deterministic and stochastic effects. Previous works show that the fluctuations can be predicted precisely when taking cycle-tocycle correlations into account. This work extends current approaches by focusing on additional dependencies within one single combustion cycle.

In view of changing climatic conditions all over the world, Green House Gas (GHG) saving related initiatives such as reducing the CO2 emissions from the mobility and transportation sectors have gained in importance. Therefore, with respect to the large U.S. market, the corresponding legal authorities have defined aggressive and challenging targets for the upcoming time frame. Due to several aspects and conditions, like hesitantly acting clients regarding electrically powered vehicles or low prices for fossil fuels, convincing and attractive products have to be developed to merge legal requirements with market constraints. This is especially valid for the market segment of Light-Duty vehicles, like SUV’S and Pick-Up trucks, which are in high demand.

Using a holistic 1D engine simulation approach for the modelling of full-transient engine operation, allows analyzing future engine concepts, including its exhaust gas aftertreatment technology, early in the development process. Thus, this approach enables the investigation of both important fields - the thermodynamic engine process and the aftertreatment system, together with their interaction in a single simulation environment. Regarding the aftertreatment system, the kinetic reaction behavior of state-of-the-art and advanced components, such as Diesel Oxidation Catalysts (DOC) or Selective Catalytic Reduction Soot Filters (SCRF), is being modelled. Furthermore, the authors present the use of the 1D engine and exhaust gas aftertreatment model on use cases of variable valve train (VVT) applications on passenger car (PC) diesel engines.

In meeting the stringent emission norms with internal engine measures, the design of the piston bowl and the nozzle configuration perform a defining role. Through 3D CFD simulations, this article shall parametrically investigate the influence of piston bowl geometry and nozzle characteristics on the performance of the combustion system. After validation of the 3D simulation model with experimental results, a Design of Experiment (DoE) method shall be applied to analyze a matrix of piston bowls with parametric variations in geometry. Further, the influence of the nozzle cone angle, hydraulic flow rate, number of holes and their combination shall be determined using systematic parameter variations with selected piston bowl designs. The performance of the various hardware configurations would be evaluated based on the exhaust emissions and fuel consumption values.

For on- and off-highway applications in 2012/2014 new legislative emissions requirements will be applied for both European (EURO 6/stage 4) and US (US 2010/Tier4 final) standards. Specifically the NOX-emission limit will be lowered down to 0.46 g/kWh (net power ≻ 56 kW (EU)/130 kW (US) - 560 kW). While for the previous emissions legislation various ways could be used to stay within the emissions limits (engine internal and aftertreatment measures), DeNOX-aftertreatment systems will be mandatory to reach future limits. In these kinds of applications fuel consumption of the engines is a very decisive selling argument for customers. Total cost of ownership needs to be as low as possible. The trade-off between fuel consumption and NOX emissions forces manufacturers to find an optimal solution, especially with regard to increasing fuel prices. In state-of-the-art calibration processes the aftertreatment system is considered separately from the calibration of the thermodynamics.

Current production of Dual Clutch Transmissions (DCTs) feature a maximum of seven speeds, which can easily be realized using three main shafts and four shift sleeves. To increase the number of gears with conventional means, more gears, shift sleeves and shafts have to be added thus increasing size, weight and cost. With the “xDCT” family, FEV has developed a series of DCT concepts which effectively minimize mechanical complexity for any given number of gears by combining two innovative ideas: “Gear generation” and “supported shifts”. In order to “generate gears”, a switchable connection between the two input shafts is installed which allows to use all gears inside the transmission with both clutches. The main challenge then is to effectively use the large number of resulting gears in a shift schedule without torque interruption. The solution is to incorporate “supported shifts” during which torque fill-in for an AMT-style gear shift is provided by the next higher gear.

Besides an excellent driving performance and power output the reduction of CO2 emission is one of the main driver for the increasing distribution of modern diesel engines. Downsizing/downspeeding, friction reduction, new combustion processes and light weight engine architecture describe additional improvement potentials. Nevertheless, these development trends have a significant influence on the noise and vibration behavior of diesel engines. Therefore measures are also necessary to compensate these acoustic disadvantages. Within this publication the most important and efficient countermeasures are described and assessed. Combustion is still one of the dominant noise sources of a modern diesel engine. Diesel knocking is annoying and the combustion noise level is typically higher than for gasoline engines.

The electrification of vehicle propulsion has changed the landscape of vehicle NVH. Pure electric vehicles (EV) are almost always quieter than those powered by internal combustion engines. However, one of the key challenges with the development of range extended electric vehicles (ReEV) is the NVH behavior of the vehicle. Specifically, the transition from the EV mode to one where the range extender engine is operational can cause significant NVH issues. In addition, the operation of the range extender engine relative to various driving conditions can also pose significant NVH concerns. In this paper internal combustion engines are examined in terms of their acoustic behavior when used as range extenders. This is done by simulating the vibrations at the engine mounting positions as well as the intake and exhaust orifice noise. By using a transfer path synthesis, interior noise components of the range extenders are calculated from these excitations.

Downsizing, down speeding and hybridization are becoming a standard in the automotive industry. This paper was initiated to answer Automobili Lamborghini R&D's question: what does downsizing mean In technical literature downsizing is often referred to as reducing displacement and, sometimes, cylinders. Through a methodological approach, analysis and experimental activities Automobili Lamborghini, with FEV's support, shows that downsizing in terms of engine friction reduction means only reduction of displacement. Using the Aventador V12 6.5 liter engine as a baseline, two 4.3 liter engines were designed, a V8 and a V12. The engine friction losses of these two engines were calculated all over the engine speed range and during the NEDC cycle utilizing a simulation tool and verified through FEV's “Strip-Method” database. This approach gives us the holistic understanding on engine components design and which technologies should be introduced for the next Lamborghini engine generation.

For turbocharged engines high specific power and torque output as well as a fast transient response are mandatory. This conflict of aims can be solved by different charging systems, for example 2-stage charging or variable turbine geometry. At the Institute for Combustion Engines (VKA) at RWTH Aachen University another alternative, the variable compressor pre swirl, was investigated for solving this conflict of aims. Based on theoretical fundamentals the potentials of a variable compressor pre swirl for transient response, low end torque, specific power output and fuel consumption were presented. These theoretical potentials were explored on turbocharger -, engine - and vehicle test bench. An extended compressor map with partial higher compressor efficiency of up to 2% was detected. The outcome of this is an increase of up to 6% in low end torque, found on engine test bench. This effect could also be validated in 1D simulation.

Future vehicles will increasingly be required to improve their efficiency, reduce both regulated and CO₂ emissions, and maintain acceptable levels of driving, safety, and noise performance. To achieve this high level of performance, they will be configured with more advanced hardware, sensors, and control technologies that will also enable their operation on a broader range of fuel properties. These capabilities offer the potential to design future vehicles to operate on the most widely available and GHG-reducing fuels. In previous studies, fuel flexibility has been demonstrated on a compression ignition bench engine and vehicle equipped with an advanced engine management system, closed-loop combustion control, and air-path control strategies. An unresolved question is whether engines of this sort can operate routinely on market gasoline while achieving diesel-like efficiency and acceptable emissions and noise levels.

The definition of vehicle and powertrain level targets is one of the first tasks toward establishing where a vehicle will reside with respect to the current or future state of industry. Though development of sound quality metrics is ongoing to better correlate objective data with subjective assessments, target setting at the vehicle level is relatively straightforward. However, realization of these targets depends on effective cascading to system and component levels. Often, component level targets are derived based on experience from earlier development programs, or based on selected characteristics observed during component level benchmarking. An approach is presented here to complement current strategies for component level target definition. This approach involves a systematic concept for definition of component NVH targets based on desired vehicle level performance and a consequent target break down.

The modern DI-diesel engine represents a valuable platform to achieve worldwide tightened CO2 standards while meeting future strengthened emission regulations in the EU and the US. Due to the simultaneous, partially contrary legal demands, new integrated and combined systems are required to allow best overall performance within the upcoming legal frames concerning pollutant emission reduction and minimization of CO2 output. As extended emission relevant areas in the engine map have to be respected in view of RDE and PEMS scenarios in EU, but also facing the LEVIII standards in the US, comprehensive and synchronized technical solutions have to be engineered. Based on furthermore optimized combustion systems with improved combustion efficiency, meaning also lowered exhaust gas temperatures, especially refined and tailored emission control systems are demanded.