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Natural gas is a promising alternative fuel for internal combustion engine application due to its low carbon content and high knock resistance. Performance of natural gas engines is further improved if direct injection, high turbocharger boost level, and variable valve actuation (VVA) are adopted. Also, relevant efficiency benefits can be obtained through downsizing. However, mixture quality resulting from direct gas injection has proven to be problematic. This work aims at developing a mono-fuel small-displacement turbocharged compressed natural gas engine with side-mounted direct injector and advanced VVA system. An injector configuration was designed in order to enhance the overall engine tumble and thus overcome low penetration.

The development of hydrogen-fueled vehicles has created the need for established fuel consumption testing methods. Until now the EPA has only accepted three methods of hydrogen fuel consumption testing, gravimetric, PVT (stabilized pressure, volume and temperature), and Coriolis mass flow; all of which necessitate physical measurements of the fuel supply [1]. BMW has developed an equation and subsequent testing methods to accurately and effectively determine hydrogen fuel consumption in light-duty vehicles using only exhaust emissions. Known as “Hydrogen-Balance”, the new equation requires no changes to EPA procedures and only slight modifications to most existing chassis dynamometers and CVS (Constant Volume Sampling) systems. The SAE 2008-01-1036, also written by BMW, explains the background as well as required equipment and changes to the CVS testing system. This paper takes hydrogen balance further by testing it against the three EPA established forms of fuel consumption.

The Hydrogen-Balance equation makes it possible to calculate the fuel economy or fuel consumption of hydrogen powered vehicles simply by analyzing exhaust emissions. While the benefits of such a method are apparent, it is important to discuss possible influencing factors that may decrease Hydrogen-Balance accuracy. Measuring vehicle exhaust emissions is done with a CVS (Constant Volume Sampling) system. While the CVS system has proven itself both robust and precise over the years, utilizing it for hydrogen applications requires extra caution to retain measurement accuracy. Consideration should be given to all testing equipment, as well as the vehicle being tested. Certain environmental factors may also play a role not just in Hydrogen-Balance accuracy, but as also in other low emission testing accuracy.

To meet LEV and EU Stage III emission requirements, it is necessary for new catalytic converters to be designed which exceed light-off temperature as quickly as possible. The technical solutions are secondary air injection, active heating systems such as the electrically heated catalytic converter, and the close coupled catalytic converter. Engine control functions are extensively used to heat the converter and will to play a significant role in the future. The concept of relocating the converter to a position close to the engine in an existing vehicle involves new conflicts. Examples include the space requirements, the thermal resistance of the catalytic coating and high temperature loads in the engine compartment.

Although hydrogen ICE engines have existed in one sort or another for many years, the testing of fuel consumption by way of exhaust emissions is not yet a proven method. The current consumption method for gasoline- and diesel-fueled vehicles is called the Carbon-Balance method, and it works by testing the vehicle exhaust for all carbon-containing components. Through conservation of mass, the carbon that comes out as exhaust must have gone in as fuel. Just like the Carbon-Balance method for gas and diesel engines, the new Hydrogen-Balance equation works on the principle that what goes into the engine must come out as exhaust components. This allows for fuel consumption measurements without direct contact with the fuel. This means increased accuracy and simplicity. This new method requires some modifications to the testing procedures and CVS (Constant Volume Sampling) system.

The study of oil emission is of essential interest for the engine development of modern cars, as well as for the understanding of hydrocarbon emissions especially during cold start conditions. A laser mass spectrometer has been used to measure single aromatic hydrocarbons in unconditioned exhaust gas of a H2-fueled engine at stationary and transient motor operation. These compounds represent unburned oil constituents. The measurements were accompanied by FID and GC-FID measurements of hydrocarbons which represent the burned oil constituents. The total oil consumption has been determined by measuring the oil sampled by freezing and weighing. It has been concluded that only 10 % of the oil consumption via exhaust gas has burned in the cylinders. A correlation of the emission of single oil-based components at ppb level detected with the laser mass spectrometer to the total motor oil emission has been found.

The results of previous Life Cycle Assessments indicate the ecological dominance of the vehicle's use phase compared to its production and recycling phase. Particularly the so-called weight-induced fuel saving coefficients point out the great spectrum (0.15 to 1.0 l/(100 kg · 100 km)) that affects the total result of the LCA significantly. The objective of this article, therefore, is to derive a physical based, i.e. scientific chargeable and practical approved, concept to determine the significant parameters of a vehicle's use phase for the Life Cycle Inventory. It turns out that - besides the aerodynamic and rolling resistance parameters and the efficiencies of the power train - the vehicle's weight, the rear axle's transmission ratio and the driven velocity profile have an important influence on a vehicle's fuel consumption.

A new category of hypereutectic aluminum liners, made by PM route is now available on the market (SILITEC) and it is successfully applied to high-pressure die casting process to produce open deck cylinder blocks. The claimed achievable engine performances over cast-iron liners (weight saving, reduction of oil consumption, optimal heat transfer, wear and friction losses reduction) justify the interest of automotive industry in developing such a technology. The paper will present the experience and the achieved results in permanent mold gravity casting with Silitec liners, where metal flow definition and temperature distribution control make the casting technique more challenging for the manufacturing of closed deck cylinder blocks.

BMW, DaimlerChrysler, Motorola and Philips present their joint development activity related to the FlexRay communication system that is intended for distributed applications in vehicles. The designated applications for powertrain and chassis control place requirements in terms of availability, reliability and data bandwidth that cannot be met by any product currently available on the market under the testing conditions encountered in an automobile. A short look back on events so far is followed by a description of the protocol and its first implementation as an integrated circuit, as well as its incorporation into a complete tool environment.

The automakers that comprise MOST® describe the reasons for this decision. First, they present the automobile industry's needs relative to multimedia networks in vehicles. Then, they present the different aspects of the MOST® technology. Multimedia networks are used in the electronics market, but they do not meet the technical and industrial constraints of the automobile electronics, which is why six automakers are working on most technology under the aegis of ""Most Cooperation.'' The transmission rate is a decisive aspect in the selection of a multimedia network. The rate of sound and video applications require fiber optics. The multimedia network rate must be adequate for a vehicle equipped with the maximum number of options, but the maximum rate is limited by the number of passengers.

The optimization of the vaporization and mixture formation process is of great importance for the development of modern gasoline direct injection (GDI) engines, because it influences the subsequent processes of the ignition, combustion and pollutant formation significantly. In consequence, the subject of this work was the development of a measurement technique based on the laser induced exciplex fluorescence (LIF), which allows the two dimensional visualization and quantification of the in-cylinder air/fuel ratio. A tracer concept consisting of benzene and triethylamine dissolved in a non-fluorescent base fuel has been used. The calibration of the equivalence ratio proportional LIF-signal was performed directly inside the engine, at a well known mixture composition, immediately before the direct injection measurements were started.

Handling behaviour is a very important aspect of modern cars, which need to reach high levels of lateral acceleration maintaining good stability and driveability. The presence of an AWD powertrain changes the response of the vehicle and then it is very important to qualify the car behavior in terms of perceived performances through objective indexes. The paper presents the development of evaluation criteria for AWD vehicles objective assessment; simulation tools and SW standard procedure has been optimised for AWD performances virtual evaluation and different architectures (locking, self-locking, visco-coupling, active differentials) are compared in terms of longitudinal, lateral and cross-coupling dynamics performances. Through the proposed methods it is possible to make vehicle system analysis using simulation model and standard procedures to classify different AWD architectures.

Centro Ricerche Fiat in collaboration with Fiat Auto vehicle test department has developed a numerical-experimental procedure in order to support on-road development and fine tuning of a new car with electric power steering. The integration of an electric power steering model, given by the supplier, in a full vehicle model, in order to evaluate steering feel objective quality indices, has allowed to improve vehicle performance in term of steering feel and reduce on-road development time.

One of the way for improving environmental performances of car propulsion system is the adoption of hybrid systems where the internal combustion engine (ICE) is coupled or temporary overtaken by an electric motor. The reference prototype of this article is the FIAT Multipla Hybrid where are possible three functional modes: Pure Electric mode, Serial Hybrid and Parallel Hybrid. Particularly it was approached the torque splitting algorithm applied to the parallel hybrid one; the work was first tested in simulation, after implemented in the electronic control units and finally tested on the field using the test bench of the 10 hybrid vehicles that belongs to the Atena Project [1].

The air conditioning system of a car uses the reverse Carnot thermodynamic cycle of a refrigerant gas. The fluids normally used have at least a direct impact on global warming, so their losses have to be avoided. A very simple method to detect refrigerant charge level was developed, using few standard sensors. Results show that it is possible to have an estimation of system charge level with satisfactory accuracy, and seems able to avoid complete loss of refrigerant.

Flame Ionization Detectors (FID) can be used to detect organic hydrocarbons that occur in plastics, lacquers, adhesives, solvents and gasoline. These substances are ionized in the hydrogen flame of the FID. The ionization current that is produced depends on the amount of hydrocarbon in the sample. With the lowering of emissions limits, measuring instruments, including the FID, have to be able to detect very low values. For SULEV (Super-Ultra Low Emissions Vehicle) measurements the accuracy and also the general applicability of the CVS (Constant Volume Sampling) measuring technique are now questioned. Basic understanding is necessary to ask the right questions. One important issue is the science behind the measurement principle of the FID. And in this case especially the influence of contamination of the operating gases, cross sensitivity and data processing on the Limit of Detection (LOD).

The Energy and Environment Test Centre (EVZ) is a complex comprising three large climatic wind tunnels, two smaller test chambers, nine soak rooms and support infrastructure. The capabilities of the wind tunnels and chambers are varied, and as a whole give BMW the ability to test at practically all conditions experienced by their vehicles, worldwide. The three wind tunnels have been designed for differing test capabilities, but share the same air circuit design, which has been optimized for energy consumption yet is compact for its large, 8.4 m₂, nozzle cross-section. The wind tunnel test section was designed to meet demanding aerodynamic specifications, including a limit on the axial static pressure gradient and low frequency static pressure fluctuations - design parameters previously reserved for larger aerodynamic or aero-acoustic wind tunnels. The aerodynamic design was achieved, in-part, by use of computational fluid dynamics and a purpose-built model wind tunnel.

A local Gaussian process regression approach is presented, which allows to model nonlinearities of internal combustion engines more accurate than global Gaussian process regression. By building smaller models, the prediction of local system behavior improves significantly. In order to predict a value, the algorithm chooses the nearest training points. The number of chosen training points depends on the intensity of estimated nonlinearity. After determining the training points, a model is built, the prediction performed and the model discarded. The approach is demonstrated with a benchmark system and air charge test bed measurements. The measurements are taken from a turbocharged SI gasoline engine with both variable inlet valve lift and variable inlet and exhaust valve opening angle. The results show how local Gaussian process regression outmatches global Gaussian process regression concerning model quality and nonlinearities in particular.

Air charge calibration of turbocharged SI gasoline engines with both variable inlet valve lift and variable inlet and exhaust valve opening angle has to be very accurate and needs a high number of measurements. In particular, the modeling of the transition area from unthrottled, inlet valve controlled resp. throttled mode to turbocharged mode, suffers from small number of measurements (e.g. when applying Design of Experiments (DoE)). This is due to the strong impact of residual gas respectively scavenging dominating locally in this area. In this article, a virtual residual gas sensor in order to enable black-box-modeling of the air charge is presented. The sensor is a multilayer perceptron artificial neural network. Amongst others, the physically calculated air mass is used as training data for the artificial neural network.

An experimental investigation of fuel consumption, exhaust emissions and heat release was performed on a prototype 1.2 liter 4 cylinder turbocharged CNG engine, which has been specifically developed and optimized in order to fully exploit natural gas potential. More specifically, the combination of a high CR of 10.1:1 and a Garrett high-performance turbocharger featuring selectable levels of boost produced a favorable efficiency map, with peak values exceeding 35%. The experimental tests were carried out in order to assess the engine performance improvement attainable through turbocharging and to define the best control strategies for this latter. The investigation included ample variations of engine speed and load, RAFR as well as trade-offs between boost level and throttle position. At each test point, in-cylinder pressure, fuel consumption and ‘engine-out’ pollutant emissions, including methane unburned hydrocarbons concentration, were measured.