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Maximizing the acoustic attenuation is one of the important design criteria of automotive exhaust systems. Although both analytical and numerical approaches exist to evaluate the acoustic transmission properties of exhaust systems, they are, at present, insufficient to model the full geometrical complexity and to accurately assess the influence of thermal and aerodynamic phenomena onto the acoustic attenuation characteristics. For this reason, an experimental test campaign is often still indispensable to evaluate the aeroacoustic performance of exhaust systems. One of the most commonly used experimental characterization techniques for flow duct systems is the two-port characterization.

Back in the first two decades of automobile development, electric propulsion was a serious competitor for the internal combustion engine. Electrically-propelled vehicles, however, soon proved unable to satisfy users' increasing performance demands in terms of range, acceleration, top speed and hill-climbing, together with such factors as operating life, initial purchase price, running costs and reliability. Engineers investigating electric propulsion today face precisely the same unwelcome legacy as their predecessors, despite many and varied attempts in the meantime to improve the components of the electric vehicle's drive system (energy storage device, motors, controller). Progress in battery development, particularly in the case of the NaS system, has nevertheless enabled us at least partly to overcome the previous problems associated with electric drive systems, though it cannot be claimed that all obstacles to its commercial application have been eliminated as yet.

Over the next decades to come, fossil fuel powered Internal Combustion Engines (ICE) will still constitute the major powertrains for land transport. Therefore, their impact on the global and local pollution and on the use of natural resources should be minimized. To this end, an extensive fundamental and practical study was performed to evaluate the potential benefits of simultaneously co-optimizing the system fuel-and-engine using diesel as an example. It will be clearly shown that the still unused co-optimizing of the system fuel-and-engine (including advanced exhaust after-treatment) as a single entity is a must for enabling cleaner future road transport by cleaner fuels since there are large, still unexploited potentials for improvements in road fuels which will provide major reductions in pollutant emissions both in vehicles already in the field and even more so in future dedicated vehicles.

Soot formation and oxidation are complex and competing processes during diesel combustion. The balance between the two processes and their history determines engine-out soot values. Besides the efforts to lower soot formation with measures to influence the flame lift-off distance for example or to use HCCI-combustion, enhancement of late soot oxidation is of equal importance for low-λ diffusion-controlled low emissions combustion with EGR. The purpose of this study is to investigate soot oxidation in a heavy duty diesel engine by statistical analysis of engine data and in-cylinder endoscopic high speed photography together with CFD simulations with a main focus on large scale in-cylinder gas motion. Results from CFD simulations using a detailed soot model were used to reveal details about the soot oxidation.

In order to avoid the undesired side effect of water condensation occurring under special environment conditions in modern xenon lamps several modifications of the serial automotive headlamps were suggested. The suggestions consist of a) desired leakage in the cover, b) anti-fog coating and c) integrated ventilation tube. These strategies were tested using two types of serial head lamps applying a condensation cycle for the simulation of the urban condition. During this condensation cycle the thermodynamic parameters, like relative air humidity and temperature, were measured at different places in the head lamp and as function of time. The modification with the integrated ventilation tube is able to improve the serial head lamp significantly. The improvement in terms of water condensation for the modification using anti-fog coating depends from the number of cooling cycles.

Advanced functionalities unthinkable a few decades ago are now being introduced into automotive vehicles through embedded systems for reasons like emission control, vehicle connectivity, safety and cooperative behaviors. As the development often involves stakeholders from different engineering disciplines and organizations, the complexity due to shared requirements, interdependencies of data, functions, and resources, as well as tight constraints in regards to timing, safety, and resource efficiency makes the system integration, quality control and assurance, reuse and change management increasingly more difficult. This calls for a more rigorous approach to the development of automotive embedded systems and components.

This paper is the third in the series of documents designed to record the progress on the SAE Plug-in Electric Vehicle (PEV) communication task force. The initial paper (2010-01-0837) introduced utility communications (J2836/1™ & J2847/1) and how the SAE task force interfaced with other organizations. The second paper (2011-01-0866) focused on the next steps of the utility requirements and added DC charging (J2836/2™ & J2847/2) along with initial effort for Reverse Power Flow (J2836/3™ & J2847/3). This paper continues with the following: 1. Completion of DC charging's 1st step publication of J2836/2™ & J2847/2. 2. Completion of 1st step of communication requirements as it relates to PowerLine Carrier (PLC) captured in J2931/1. This leads to testing of PLC products for Utility and DC charging messages using EPRI's test plan and schedule. 3. Progress for PEV communications interoperability in J2953/1.

Automatic Crash Notification (ACN) technology provides an opportunity to rapidly transmit crash characteristics to emergency care providers in order to improve timeliness and quality of care provided to occupants in the post crash phase. This study evaluated the relative value of crash attributes in providing useful information to assist in the identification of crashes where occupants may be seriously injured. This identification includes an indication of whether a crash is likely to require a level of emergency response with higher priority than is needed for most crashes reported by ACN Systems. The ability to predict serious injury using groupings of variables has been determined. In this way, the consequence of not transmitting each variable can be estimated. In addition, the incremental benefit of voice communication is shown.

In this work, we present an unsteady flamelet progress variable approach for diesel engine CFD combustion modeling. The progress variable is based on sensible enthalpy integrated over the flamelet and describes the transient flamelet ignition process. By using an unsteady flamelet library for the progress variable, the impact of local effects, for example variations in the turbulence field, effects of wall heat transfer etc. on the autoignition chemistry can be considered on a cell level. The coupling between the unsteady flamelet library and the transport equation for total enthalpy follows the ideas of the representative interactive flamelet approach. Since the progress variable gives a direct description of the state in the flamelet, the method can be compared to having a flamelet in each computational cell in the CFD grid.

The effects of EGR on diesel combustion were visually examined in a single-cylinder heavy duty research engine with a low compression ratio, low swirl, a CR fuel injection system and an eight-orifice nozzle. Optical access was primarily obtained through the cylinder head. The effects of EGR were found to be significant. NOx emissions were reduced from over 500 ppm at 0% EGR to 5 ppm at 55% EGR. At higher levels of EGR (approximately 35% or more) there was a loss in efficiency. Constant fuel masses were injected. Results from the optical measurements and global emission data were compared in order to obtain a better understanding of the spray behaviour and mixing process. Optical measurements provide fundamental insights by visualizing air motion and combustion behaviour. The NOx reductions observed might be explained by reductions in oxygen concentration associated with the increases in EGR.

Experiments were conducted with a single cylinder heavy duty research engine, based on the geometry of a Volvo Powertrain D12C production engine. For these tests the engine was configured with a low compression ratio, low swirl, common rail fuel injection system and an eight-orifice nozzle. The combustion process was visualized by video via an inserted endoscope. From the resulting images temperatures were evaluated with the two-color method. In addition, the combustion and emission formation were simulated using the multiple flamelet concept implemented in the commercial CFD code STAR-CD. The models used in this paper are considered state-of-the-art. The purpose of this paper is to demonstrate the possibilities offered by combining several methods in the evaluation of novel engine concepts. Therefore, results from the optical measurements, the CFD simulations and global emission experimental data were compared.

BMW has undertaken a comprehensive program including laboratory simulation rig tests, engine dynamometer and fleet evaluations to evaluate the influence of mechanical and fuel variables on induction system deposits in modern port fuel injected (PFI) spark ignition engines. The primary focus of the program has been the deposit buildup on intake valves (IVD) and associated driveability impacts. Initial investigations of engine modifications yielded only marginal improvements relative to deposit build-up and, therefore this led to investigations of the effect of gasolines and additives. Fuel quality, type, quantity of additives and alcohol content have all been found to be major contributing factors to intake valve deposition. In addition, intake valve deposit weight has been directly related to warm-up phase driveability concerns using a newly developed driveability procedure.

The idea of keeping a vehicle safe and secure throughout its whole life cycle, as well as having the opportunity to add functionality after initial delivery, is the key motivation behind automotive software updates. Today, safety or security issues that appear after vehicle delivery need to be resolved by starting a recall campaign. These campaigns require the vehicle user to visit a car repair workshop to get an update. Over The Air (OTA) software updates, being location-independent, can pave the way for higher update frequencies and more efficiency regarding customer satisfaction, resource consumption as well as safety and security. In this paper we analyze requirements for OTA software updates phrased in various standards and regulations as well as in existing development and type approval processes. Prevailing challenges for OTA updates are extracted to identify necessary activities and artifacts within the procedure.

This paper summarises the potential for the use of a gasoline direct injection engine for fuel economy benefits. Various engine technologies are compared for the greatest reduction in fuel consumption at the steady state point 2000rpm/2 bar. This is an important driving point in the EU cycle. The direct injection engine when used in an unthrottled lean stratified mode shows the greatest potential. Calculations show a fuel economy of a middle class vehicle can be increased by 12% using a DI over the EU cycle. The catalytic aftertreatment system is discussed and it is concluded that a close coupled pre-catalyst, a NOx trap and double injection are a good overall solution for the minimisation of exhaust gas emissions from a DI engine.

Thermographic phosphors thermometry was used to measure engine valves and transparent piston temperatures in two dimensions as well point wise of a running, optically accessible, gasoline direct injection engine. The engine, fueled with isooctane, was operated in continuous and skip-fire mode at 1200 and 2000 rpm. A calibration of the phosphorescence lifetime and spectral properties against temperature allowed temperature measurements between 25 and 600°C. Results from the measurements show the potential of the technique for two-dimensional mapping of engine walls, valves and piston temperatures inside the cylinder.

Piston temperature experiments were conducted in a single-cylinder heavy-duty Diesel research engine, based on the Volvo Powertrain D12C engine both by use of optical temperature sensitive phosphor and of thermocouples mounted on the piston surface. In the former case, a thin coating of a suitable thermographic phosphor was applied to the areas on the piston surface to be investigated. The optical measurements of piston temperatures made involved use of an optical window and of an endoscope. The possibility of using optical fibres into guide light in and out of the engine was also investigated. Results of the optical and of the thermocouple measurements were compared and were also related to more global data with the aim of exploring the use of thermographic phosphors for piston- temperature measurements in Diesel engines. Thermographic phosphors thermometry was found to represent an alternative to the thermocouple method since it easily can be applied to various piston geometries.

To reduce vehicle development cycles it is necessary to perform numerical durability analyses in an early development phase. Typically there is no physical prototype available at that time hence there are no measured data, either from the proving ground or from test rigs. This paper presents an alternative method to predict the required loads. Using Multi-Body Simulation (MBS), the loads prediction process is performed for an unconstrained vehicle, which means that vehicle body position and orientation are allowed to change. Of particular interest are the time series of the loads acting at components of the front-and the rear-suspension, as well as on the body structure of the vehicle. For the loads prediction BMW uses the so called Hybrid-Road-Approach developed by LMS. After an initial pilot project demonstrating that approach's feasibility and potential, the project presented below is the first run of that approach by BMW in their productive environment.

Rotor-only ducted low-pressure axial fans play a crucial role in automotive thermal management of the tightly packed under-hood region. Most current scientific work concerning low-pressure axial fans investigate the aerodynamic performance of these fans while operating with uniform inlet flow conditions. This is rarely the case in real-world applications. This work aims to investigate the aerodynamic performance of low-pressure axial fans operating with upstream blockages. First, a validation study is performed in the absence of any upstream blockage. Numerical results are compared against publicly available experimental data. Steady-state, Reynolds-Averaged Navier Stokes (RANS) analysis is performed on a single-blade passage. The validation study also evaluates the choice of turbulence model and suggests the use of the k- ε turbulence model with wall functions for the best comparison against experimental data.