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Electrified vehicles are particularly quiet, especially at low speeds due to the absence of combustion noises. This is why there are laws worldwide for artificial driving sounds to warn pedestrians. These sounds are generated using a so-called Acoustic Vehicle Alerting System (AVAS) which must maintain certain minimum sound pressure levels in specific frequency ranges at low speeds. The creation of the sound currently involves an iterative and sometimes time-consuming process that combines composing the sound on a computer with measuring the levels with a car on an outside noise test track. This continues until both the legal requirements and the subjective demands of vehicle manufacturers are met. To optimize this process and reduce the measurement effort on the outside noise test track, the goal is to replace the measurement with a simulation for a significant portion of the development.

In view of BS-VI emission norms implementation in Commercial Vehicle (CV) application, the emissions are not only confirmed in standard condition but also in non-standard condition including different combinations of ambient temperature and pressure especially for checking the emission in WNTE cycle. However, achieving the emissions in different environmental conditions require physical emission calibration to be performed in those conditions. Hence, engine must be calibrated in climatic test chambers to ensure emission in different climatic conditions leading to multifold increase in the calibration effort. With addition of BS-VI emission regulation, After Treatment System (ATS) is a mandatory requirement to reduce the tail pipe emissions. Efficient functioning of ATS requires enough heating to convert the engine out emissions. Vehicle level Real Drive Emission (RDE) measurement without Conformity Factor (CF) limitation are added as an important legislative requirement.

The major objective of this paper is to develop thermal management strategy targeting optimum performance of Selective Catalytic Reduction (SCR) catalyst in a Medium Duty Diesel Engine performing in BS6 emission cycles. In the current scenario, the Emissions Norms are becoming more stringent and with the introduction of Real Drive Emission Test (RDE) and WHTC test comprising of both cold and hot phase, there is a need to develop techniques and strategies which are quick to respond in real time to cope with emission limit especially NOx. SCR seems to be suitable solution in reducing NOx in real time. However, there are limitations to SCR operating conditions, the major being the dosing release conditions which defines the gas temperature at which DEF (Diesel Exhaust Fluid) can be injected as DEF injection at lower gas temperatures than dosing release will lead to Urea deposit formation and will significantly hamper the SCR performance.

The objective of this study was to reduce pollutant emissions during cold start conditions in a spark-ignited direct injection engine, by exploring the potential of oxygenated fuels. With their high oxygen content and lack of direct C-C bonds, they effectively reduce particle number (PN) and NOx emissions under normal conditions. Methanol was chosen due to its wide availability. As methanol is toxic to humans and associated with cold-start issues, a second promising synthetic fuel was selected to be benchmarked against gasoline, comprising 65 vol% of dimethyl carbonate and 35 vol% of methyl formate (C65F5). Currently, there is a lack of detailed investigations on the cold start performance for both oxygenated fuels utilizing today’s injector capabilities. Spray measurements were caried out in a constant volume chamber to assess the spray of C65F35. Reduced fuel temperature increased spray-penetration length and compromised fast vaporization.

Photochromism is a reversible color change phenomenon based on chemical reactions caused by light illumination. In the present study, this technique is applied to visualize the lubricating oil and fuel around the piston rings in the gasoline engine. The oil film was colored with a UV laser and photographed by synchronizing the shutter of a high-speed camera with a flashlight. The color density was evaluated as a value of absorbance, calculated from images taken at two different wavelengths and two different times before and after the coloration. The authors performed photochromism visualization experiments in an engine under motored operation. However, using photochromic dyes that are robust to temperature changes makes it possible to visualize the engine under fired operation. The experiment was conducted mainly by switching to the motored operation for a fixed time between the fired operations.

A novel algorithm-based approach is employed in this publication to calculate multiple direct injection patterns for spark ignition engines. The algorithm is verified by investigating the combustion and emission behavior of a single-cylinder research engine. State-of-the-art standard exhaust gas analyzers, a particle counter and an additional FTIR analyzer enable in-depth investigation of engine exhaust gas composition. With the upcoming worldwide pollutant emission targets, the emission limits will be reduced while the test procedures’ requirements to the engine increase. Special attention to the engine-out emissions must be paid during cold-start, during which the aftertreatment system lacks sufficient pollutant emission conversion efficiency. With advanced injection control, the engine-out emissions can be reduced and exhaust aftertreatment heat-up can be accelerated.

This paper provides an overview of possible engine design optimizations by utilizing highly knock-resistant potential greenhouse gas (GHG) neutral synthetic fuels. Historically the internal combustion engine was tailored to and highly optimized for fossil fuels. For future engine generations one of the main objectives is to achieve GHG neutrality. This means that either carbon-free fuels such as hydrogen or potential greenhouse gas neutral fuels are utilized. The properties of hydrogen make its use challenging for mobile application as it is very diffusive, not liquid under standard temperature/pressure and has a low volumetric energy density. C1-based oxygenated fuels such as methanol (MeOH), dimethyl carbonate (DMC) and methyl formate (MeFo) have properties like conventional gasoline but offer various advantages. Firstly, these fuels can be produced with renewable energy and carbon capture technologies to be GHG neutral.

The safety of BEVs in driving, charging and parking condition is essential for the success of electrification in automotive industry as well as key driver of any future development of Li-Ion HV battery. AVL has developed a unique simulation approach in which the multi-physical behavior of the single cell in thermal runaway is modelled and applied to module, pack or vehicle level. In addition and beside this cell behavior, various more physical phenomena during thermal propagation on pack level are considered and predicted by the simulation method: component melting, ignition and flammibilty of venting gas and HV failures.

Future emission regulations require further development for internal combustion engines operating on gasoline. To comply with such regulations and simultaneously improve fuel efficiency, major development trends are found in reduced displacements, increased compression ratios and turbocharging. To counteract such engines’ increased tendencies to knocking combustion, direct fuel injection systems are necessarily applied. Compared to standard port fuel injection, direct injection systems cause increased particle emissions. State-of-the-art magnet-driven gasoline direct injectors are capable of realizing various injection events of small injected mass per event and short dwell time between one another. Thereby, they facilitate multiple injection strategies, able to overcome the drawbacks of direct injection systems in relation to exhaust emissions. However, the full potential of multiple injection strategies is not yet taken advantage of.

In this paper, the multi-physical simulation workflow from electromagnetics to structural dynamics for a squirrel-cage induction machine is explored. In electromagnetic simulations, local forces and rotor torque are calculated for specific speed-torque operation points. In order to consider non-linearities and interaction with control system as well as transmission, time-domain simulations are carried out. For induction machines, the computational effort with full transient numerical methods like finite element analysis (FEA) is very high. A novel reduced order electro-mechanical model is presented. It still accounts for vibro-acoustically relevant harmonics due to pulse-width modulation (PWM), slotting, distributed winding and saturation effects, but is substantially faster (minutes to hours instead of days to weeks per operation point).

HTOE (High Temperature Operation Endurance) and PTCE (Power Thermal Cycle Endurance) tests are typically performed according automotive group standards, such as LV 124 [1], VW80000 [2], FCA CS.00056 [3] or PSA B21 7130 [4]. The LV 124-2 group standard, composed by representatives of automobile manufacturers like Audi AG, BMW AG, Volkswagen AG and Porsche AG describes a wide range of environmental tests and their requirements. In addition, calculation parameters and a method are given in the standard. These group standard tests are often attributed to IEC 60068-2-2 [5] for HTOE and IEC 60068-2-14 [6] for PTCE. As both of these tests are typically of long duration, fundamentally linked to reliability (therefore requiring a statistically significant number of samples) and of considerable importance to power electronic, they are worthy of additional scrutiny for automotive developers as most automotive development moves towards electrification.

The European Commission has released strict emission regulations for passenger cars in the past decade in order to improve air quality in cities and limit harmful emission exposure to humans. In the near future, even stricter regulations containing more realistic/demanding driving scenarios and covering more exhaust gas components are expected to be released. Passenger cars fueled with gasoline are one contributor to unhealthy air conditions, due to the fact that gasoline engines emit harmful air pollutants. One option to minimize harmful emissions would be to utilize specifically tailored, low emission synthetic fuels or fuel blends in internal combustion engines. Methyl formate and dimethyl carbonate are two promising candidates to replace or substitute gasoline, which in previous studies have proven to significantly decrease harmful pollutants.

Wet running multi-plate clutches and brakes are important components of modern automotive and industrial powertrains. In the open stage, drag losses occur due to fluid shearing. This can subsequently lead to a perceptible reduction in the overall drivetrain efficiency. Injection or dip lubrication is used, depending on the application and the requirements. For the former a deep fundamental understanding already exists, whereas up until now the latter has not been extensively investigated. This contribution gives a detailed insight into the experimental research of the drag losses of wet running multi-plate clutches at dip lubrication. In a base study, the flow conditions and origins of the drag torque generation were investigated. Built on this, the effects of operating and geometry parameters, such as oil viscosity and level, clearance, groove design, plate size and number of gaps on the drag loss characteristic, were determined based on full factorial testing.

Wet Clutches are used in automotive powertrains to enable compact designs and efficient gear shifting. During the slip phase of engagement, significant flash temperatures arise at the friction disc to separator interface because of dissipative frictional losses. An important aspect of the design process is to ensure the interface temperature does not exceed the material temperature threshold at which accelerated wear behavior and/or thermal degradation occurs. During the early stages of a design process, it is advantageous to evaluate numerous system and component design iterations exposed to plethora of possible drive cycles. A simulation tool is needed which can determine the critical operational conditions the system must survive for performance and durability to be assured. This paper describes a time-efficient multiphysics model developed to predict clutch disc temperatures with a runtime in the order of minutes.

Synthetic fuels for internal combustion engines offer CO2-neutral mobility if produced in a closed carbon cycle using renewable energies. C1-based synthetic fuels can offer high knock resistance as well as soot free combustion due to their molecular structure containing oxygen and no direct C-C bonds. Such fuels as, for example, dimethyl carbonate (DMC) and methyl formate (MeFo) have great potential to replace gasoline in spark-ignition (SI) engines. In this study, a mixture of 65% DMC and 35% MeFo (C65F35) was used in a single-cylinder research engine to determine friction losses in the piston group using the floating-liner method. The results were benchmarked against gasoline (G100). Compared to gasoline, the density of C65F35 is almost 40% higher, but its mass-based lower heating value (LHV) is 2.8 times lower. Hence, more fuel must be injected to reach the same engine load as in a conventional gasoline engine, leading to an increased cooling effect.

Current developments in automotive industry such as hybrid powertrains and the continuously increasing demands on emission control systems, are pushing complexity still further. Validation of such systems lead to a huge amount of test cases and hence extreme testing efforts on the road. At the same time the pressure to reduce costs and minimize development time is creating challenging boundaries on development teams. Therefore, it is of utmost importance to utilize testing and validation prototypes in the most efficient way. It is necessary to apply high levels of instrumentation and collect as much data as possible. And a streamlined data pipeline allows the fleet managers to get new insights from the raw data and control the validation vehicles as well as the development team in the most efficient way. In this paper we will demonstrate a data-driven approach for validation testing.

On the way to a climate-neutral mobility, synthetic fuels with their potential of CO2-neutral production are currently in the focus of internal combustion research. In this study, the C1-fuels methanol (MeOH), dimethyl carbonate (DMC), and methyl formate (MeFo) are tested as pure fuel mixtures and as blend components for gasoline. The study was performed on a single-cylinder engine in two configurations, thermodynamic and optical. As pure C1-fuels, the previously investigated DMC/MeFo mixture is compared with a mixture of MeOH/MeFo. DMC is replaced by MeOH because of its benefits regarding laminar flame speed, ignition limits and production costs. MeOH/MeFo offers favorable particle number (PN) emissions at a cooling water temperature of 40 °C and in high load operating points. However, a slight increase of NOx emissions related to DMC/MeFo was observed. Both mixtures show no sensitivity in PN emissions for rich combustions. This was also verified with help of the optical engine.

In the near future, pollutant and GHG emission regulations in the transport sector will become increasingly stringent. For this reason, there are many studies in the field of internal combustion research that investigate alternative fuels, one example being oxygenated fuels. Additionally, the design of engine components needs to be optimized to improve the thresholds of clean combustion and thus reduce particulates. Simulations based on PRiME 3D® for dynamic behaviors inside the piston ring group provide a guideline for experimental investigation. Gas flows into the combustion chamber are controlled by adjusting the piston ring design. A direct comparison of regular and synthetic fuels enables to separate the emissions caused by oil and fuel. This study employed a mixture of dimethyl carbonate (DMC) and methyl formate (MeFo).

In this study a mixture of dimethyl carbonate (DMC) and methyl formate (MeFo) was used as a synthetic gasoline replacement. These synthetic fuels offer CO2-neutral mobility if the fuels are produced in a closed CO2-cycle and they reduce harmful emissions like particulates and NOX. For base potential investigations, a single-cylinder research engine (SCE) was used. An in-depth analysis of real driving cycles in a series 4-cylinder engine (4CE) confirmed the high potential for emission reduction as well as efficiency benefits. Beside the benefit of lower exhaust emissions, especially NOX and particle number (PN) emissions, some additional potential was observed in the SCE. During a start of injection (SOI) variation it could be detected that a late SOI of DMC/MeFo has less influence on combustion stability and ignitability. With this widened range for the SOI the engine application can be improved for example by catalyst heating or stratified mode.

In this study, a fully optically accessible single-cylinder research engine is the basis for the visualization and generation of extensive knowledge about the in-cylinder processes of mixture formation, ignition and combustion of oxygenated synthetic fuels. Previous measurements in an all-metal engine showed promising results by using a mixture of dimethyl carbonate and methyl formate as a fuel substitute in a DISI-engine. Lower THC and NOx emissions were observed along with a low PN-value, implying low-soot combustion. The flame luminosity transmitted via an optical piston was split in the optical path to simultaneously record the natural flame luminosity with an RGB high-speed camera. The second channel consisted of OH*-chemiluminescence recording, isolated by a bandpass filter via an intensified monochrome high-speed camera.