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The spatial distribution of internal exhaust gas recirculation (EGR) is evaluated in an optically accessible direct injection spark ignition engine using near infrared laser absorption to visualize the distribution of the H2O molecule. The obtained overall internal exhaust gas recirculation compares well to gas-exchange cycle calculations and the spatial distributions are consistent with those measured with inverse LIF. The experimental procedures described in this report are designed to be simple and rapidly implemented without the need to resort to unusual optical components. The necessary spectral data of the selected absorption line is obtained from the HITEMP database and is validated with prior experiments carried out in a reference cell. Laser speckle in the images is effectively reduced using a ballistic diffuser.

Tapping of one or more torques (ranges 10 Nm and 60 Nm) on the steering column for the purpose of servo control must satisfy high accuracy requirements on the one hand and high safety requirements on the other hand. A suggestion for developing a low-cost solution to this problem is described below: Strain gages optimally satisfy both these requirements: However, for cost reasons, these are not applied directly to the steering column but to a prefabricated, flat steel rod which is laser welded to the torque rod of the steering column. The measuring direction of the strain gages is under 45° to the steering column axis. The strain gages are either vacuum metallized onto the support rod as a thin film or laminated in a particularly low-cost way by means of a foil-type intermediate carrier.

Increasingly stringent tailpipe emissions regulations have prompted renewed interest in catalyst heating technology – where an integrated device supplies supplemental heat to accelerate catalyst ‘light-off’. Bosch and Boysen, following a collaborative multi-year effort, have developed a Rapid Catalyst Heating System (RCH) for gasoline-fueled applications. The RCH system provides upwards of 25 kW of thermal power, greatly enhancing catalyst performance and robustness. Additional benefits include reduction of precious metal loading (versus a ‘PGM-only’ approach) and avoidance of near-engine catalyst placement (limiting the need for enrichment strategies). The following paper provides a technical overview of the Bosch/Boysen (BOB) Rapid Catalyst Heating system – including a detailed review of the system’s architecture, key performance characteristics, and the associated impact on vehicle-level emissions.

Particulate emissions from Gasoline Direct Injection (GDI) engines have been an important topic of recent research interest due to their known environmental effects. This review paper will characterise the influence of different gasoline direct injection fuel systems on particle number (PN) emissions. The findings will be reviewed for engine and vehicle measurements with appropriate driving cycles (especially real driving cycles) to evaluate effects of the fuel injection systems on PN emissions. Recent technological developments alongside the trends of the influence of system pressure and nozzle design on injector tip wetting and deposits will be considered. Besides the engine and fuel system it is known that fuel composition will have an important effect on GDI engine PN emissions. The evaporation qualities of fuels have a substantial influence on mixture preparation, as does the composition of the fuel itself.

The present paper concentrates on the option of catalytic autothermal reforming of gasoline for fuel cell applications. Major parameters of this process are the “Steam to Carbon Ratio” S/C and the air to fuel ratio λ. Computations assuming thermodynamic equilibrium in the autothermal reactor outlet (ATR) were carried out to attain information about their proper choice, as failure in adjusting the parameters within narrow limits has severe consequences on the reforming process. In order to quantify velocity distribution just ahead the catalyst and to evaluate mixing uniformity we designed an ATR featuring an optical access: Thus flow visualization using PIV (Particle Image Velocimetry) and LIF (Laser Induced Fluorescence) technique is possible. Preliminary PIV-results are presented and compared with CFD computations (Computational Fluid D ynamics).

This study presents measurements of transient flow field and spray structures inside an optically accessible DISI (direct-injection spark-ignition) internal combustion engine. The flow field has a direct effect upon mixture and combustion processes. Given the need to increase the efficiency and performance of modern IC engines and thus reduce emissions a detailed understanding of the flow field is necessary. The method of choice was high-speed two-component particle image velocimetry (PIV) imaging a large field of view (43 x 44 mm₂). To capture the temporal evolution of the main flow features the repetition rate was set to 6 kHz which resolves one image per 1° crank angle (CA) at 1000 rpm. The crank angle range recorded was the latter half of the compression stroke at various engine speeds as well as various charge motions (neutral, tumble and swirl). Moreover, consecutive cycles were recorded allowing a detailed investigation of cycle-to-cycle variations.

If a sensor shall be applied in motor vehicles, all the components of the sensor must fulfil special requirements. Particular attention must be paid to the installation of the sensitive element and to the adaptation to which the sensor is to be put. The objective of this paper is to illustrate these demands more closely using three different types of sensors as examples: a displacement sensor, a pressure sensor and an acceleration sensor.

The car industry has reached a point where electronic systems, which were so far essentially autonomous, begin to grow together to a Car-Wide Web. The main driving force is the demand for more safety, security, and comfort implemented economically. Already various parties are working on control networks. In the long run, vehicle motion and dynamic systems, safety, security, comfort as well as mobile multimedia systems will integrate and reach out for the vision of accident-free, comfortable, and well-informed driving. As a foundation for a Car-Wide Web, Bosch is developing an open architecture called CARTRONIC. The essence of CARTRONIC is to define structuring rules, modeling rules and patterns for total, integrated control of vehicles. The rules and patterns allow the mapping of high-level functions onto several physical implementations, for instance one logical description of functional connections could be created for cars with different equipment packages.

Passenger car DI Diesel engines need a flexible fuel injection system. Bosch develops a common rail system for this purpose. Besides variation of fuel quantity and start of injection, it permits to choosing freely injection pressure inthe rangeof 150 to 1400 barand injecting fuel in several portions. These new means will contribute to further improvements of DI engines concerning noise, exhaust emissions and engine torque.

Common Rail provides additional flexibility for the design and application of a diesel injection system. Contrary to conventional injection systems pressure generation and injection are decoupled in the common rail system. The injection pressure can be selected independent of engine speed and injected fuel quantity within certain limits. The fuel combustion and the corresponding noise can be improved by increasing the fuel pressure up to 1400 bar and introducing pilot injection or multiple injection. Furthermore the common rail system can replace conventional injection systems without requiring major engine modifications. BOSCH will provide this new injection system for the whole range of applications from light duty (30 kW per cylinder) to heavy duty vehicles (50 kW per cylinder).

The fuel spray behavior in the near nozzle region of a gasoline injector is challenging to predict due to existing pressure gradients and turbulences of the internal flow and in-nozzle cavitation. Therefore, statistical parameters for spray characterization through experiments must be considered. The characterization of spray velocity fields in the near-nozzle region is of particular importance as the velocity information is crucial in understanding the hydrodynamic processes which take place further downstream during fuel atomization and mixture formation. This knowledge is needed in order to optimize injector nozzles for future requirements. In this study, the results of three experimental approaches for determination of spray velocity in the near-nozzle region are presented. Two different injector nozzle types were measured through high-speed shadowgraph imaging, Laser Doppler Anemometry (LDA) and X-ray imaging.

The study presented in this paper focuses on measures to minimize exhaust gas emissions to meet SULEV targets on a V6 engine by using a cost efficient system configuration. The study consists of three parts. A) In the first stage, the influence of engine management both on raw emissions and catalyst light off performance was optimized. B) Afterwards, the predefined high cell density catalyst system was tested on an engine test bench. In this stage, thermal data and engine out emissions were used for modeling and prediction of light-off performance for further optimized catalyst concepts. C) In the final stage of the program, the emission performance of the test matrix, including high cell density as well as multifunctional single substrate systems, are studied during the FTP cycle. The presented results show the approach to achieve SULEV emission compliance with innovative engine control strategies in combination with a cost effective metallic catalyst design.

This paper presents the development of a novel direct coil cooling approach which can enable high performance for electric traction motor, and in further significantly reduce motor losses. The proposed approach focuses on bypassing critical thermal resistances in motor by cooling coils directly in stator slots with oil flow. Firstly, the basic configuration and features are shown: sealed stator slots to air gap, pressure reservoirs on both side of the slots and slot channels for oil flow. The key to enhance thermal performance of the motor here is based on introducing fluid guiding structure in the slot channels. Next, heat transfer in the channel with guiding structure is investigated by CFD and compared with bare slot channel without guiding structure. For studying the effectiveness of proposed cooling concept, numerical analysis is conducted to compare it with HEV favored oil impingement cooling.

Meeting current exhaust emission standards requires rapid catalyst light-off. Closed-coupled catalysts are commonly used to reduce light-off time by minimizing exhaust heat loss between the engine and catalyst. However, this exhaust gas system design leads to a coupling of catalyst heating and engine operation. An engine-independent exhaust gas aftertreatment can be realized by combining a burner heated catalyst system (BHC) with an underfloor catalyst located far away from the engine. This paper describes some basic characteristics of such a BHC system and the results of fitting this system into a Volkswagen Touareg where a single catalyst was located about 1.8 m downstream of the engine. Nevertheless, it was possible to reach about 50% of the current European emission standard EU 4 without additional fuel consumption caused by the BHC system.

In order to optimize spray layouts of commonly used high-pressure injectors for gasoline direct injection (GDI) engines featuring multi-hole valve seats, a detailed understanding of the cause-effect relation between inner spray hole geometries and inner flow conditions, initializing the process of internal mixture formation, is needed. Therefore, a novel measurement setup, capable of determining spray hole individual mass flow rates, is introduced and discussed. To prove its feasibility, a 2-hole configuration is chosen. The injected fuel quantities are separated mechanically and guided to separate pressure tight measurement chambers. Each measurement chamber allows for time resolved mass flow rate measurements based on the HDA measurement principle (German: “Hydraulisches Druck-Anstiegsverfahren”).

In order to reduce the spark-ignition engine exhaust-gas emission and fuel consumption, it is essential that the required air/fuel ratio is maintained under all operating conditions. An important contribution to this claim is delivered by the injection valve by metering the fuel precisely and producing fine atomization. In this report experimental methods to get specific measuring information and methods for optimizing flow in injection valves are described. Original valves as well as large-scale models were used for the investigations concerning the steady and unsteady-flow characteristics, and were equipped with a number of different sensors. Holograms of the short-time recording of the spray cone are generated and used for the quantification of the atomization quality when injecting into atmospheric pressure and into vacuum, thus complying with the conditions encountered in the engine intake-manifold.

The particulate emissions can be reduced by increasing injection pressure. The NOx-emission can be lowered to the required amount with a retarded injection-begin. These measures raise fuel consumption by approximately 8-10 %. To avoid blue smoke from the cold engine, it is advantageous that the fuel injection is advanced during the warm-up period. These statements apply for injection systems with unit injectors as well as for pump-line-nozzle-systems. In this paper, the pump-line-nozzle-system will be described. With this system, injection pressures of 1200 to 1400 bar at the injection nozzle are reached. The injection-begin can be changed with a control-sleeve in-line pump. The injection-begin and fuel quantity can be flexibly and accurately adjusted by means of an electronic governor.

The fuel-independent particulate emissions of a direct injection gasoline engine were investigated. This was done by running the engine with reference gasoline at four different loads and then switching to hydrogen or methane port fuel operation and comparing the resulting particulate emissions and their size distribution. Differences in the combustion characteristics of hydrogen and gasoline were accounted for by diluting the inlet air with nitrogen and matching the pressure or heat release traces to those of gasoline operation. Methane operation is expected to generate particulate emissions lower by several orders of magnitude compared to gasoline and hydrogen does not contribute to carbon soot formation because of the lack of carbon atoms in the molecule. Thus, any remaining particulate emissions at hydrogen gas operation must arise from non fuel related sources, e.g. from lubrication oil, metal abrasion or inlet air.

In order to optimize the performance and emission of engines, advanced control and diagnostic systems require detailed feedback information about the combustion process. In this context, cost-effective solutions are of interest. The contribution describes a method for reconstructing cylinder-individual features of each combustion cycle by processing the instantaneous fluctuations of the engine speed and the in-cylinder pressure of one cylinder. Model-based torque estimation, analyzing both of the signals simultaneously, provides an accurate estimation of the mean indicated pressure. Using this method, a new algorithm for advanced misfire detection is presented. Furthermore, a new pressure model with a feasible number of parameters is proposed. It is combined with the torque estimation in order to reconstruct the unknown pressure traces of the cylinders not equipped with sensors.

We propose a novel method to real-time in-cylinder pressure estimation by processing structure-borne sound measurements. It has been shown that knowledge of the in-cylinder pressure opens the door to robust misfire detection and sophisticated closed loop engine control schemes. However, the costs of such sensors have inhibited their use in production engines. On the other hand, acceleration sensors are of low cost and already mounted on modern production engines for knock detection. Since structure-borne sound is measured on the surface of the engine, all cylinders are simultaneously observed by one sensor. A simple physically based model, describing the speed dependence of the transfer behavior from each in-cylinder pressure to structure-borne sound is developed. Based on this model, a method for identifying the parameterized transfer function speed independently is developed.