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A consortium of CONCAWE, EUCAR and the EU Commission's JRC carried out a Well-to-Wheels analysis of a wide range of automotive fuels and powertrains. The study gives an assessment of the energy consumption and greenhouse gas emissions for each pathway. It also considers macroeconomic costs and the market potential of alternative fuels.

In Motorsports the understanding of the real engine performance within a complete circuit lap is a crucial topic. On the basis of the telemetry data the engineers are able to monitor this performance and try to adapt the engine to the vehicle's and race track's characteristics and driver's needs. However, quite often the telemetry is the sole analysis instrument for the Engine-Vehicle-Driver (EVD) system and it has no prediction capability. The engine optimization for best lap-time or best fuel economy is therefore a topic which is not trivial to solve, without the aid of suitable, reliable and predictive engineering tools. A complete EVD model was therefore built in a GT-SUITE™ environment for a Motorsport racing car (STCC-VW-Scirocco) equipped with a Compressed Natural Gas (CNG) turbocharged S.I. engine and calibrated on the basis of telemetry and test bench data.

In order to reach OEMs acoustic treatment targets (improving performance while minimizing the weight and cost impact), we have developed an original hybrid approach called “Vehicle Acoustic synthesis method”[1] to simulate - and therefore to optimize - noise treatments for both insulation and absorption, and to calculate the resulting Sound Pressure Level (SPL) at ear points for the middle and high frequency range. To calculate the SPL, we identify equivalent volume velocity sources from intensity measurements, and combine them to acoustic transfer functions (panel/ear) measured or computed with ray tracing codes using the reciprocity principle. Compared to our first approach [1], this paper shows a new measurement technique using pressure-particle velocity probes [2]. This technique allows to reduce acquisition time by a factor four, and makes therefore possible a synthesis method on a complete car within two weeks.

In order to address the CO₂ emissions issue and to diversify the energy for transportation, CNG (Compressed Natural Gas) is considered as one of the most promising alternative fuels given its high octane number. However, gaseous injection decreases volumetric efficiency, impacting directly the maximal torque through a reduction of the cylinder fill-up. To overcome this drawback, both independent natural gas and gasoline indirect injection systems with dedicated engine control were fitted on a RENAULT 2.0L turbocharged SI (Spark Ignition) engine and were adapted for simultaneous operation. The main objective of this innovative combination of gas and liquid fuel injections is to increase the volumetric efficiency without losing the high knocking resistance of methane.

An innovative alternative to overcome the load limits of the early injection highly premixed combustion concept consists of taking advantage of the intrinsic characteristics of two-stroke engines, since they can attain the full load torque of a four-stroke engine as the addition of two medium load cycles, where the implementation of this combustion concept could be promising. In this frame, the main objective of this investigation focuses on evaluating the potential of the early injection HPC concept using a conventional diesel fuel combined with a two-stroke poppet valves engine architecture for pollutant control, while keeping a competitive engine efficiency. On a first stage, the HPC concept was implemented at low engine load, where the concept is expected to provide the best results, by advancing the start of injection towards the compression stroke and it was confirmed how it is possible to reduce NOX and soot emissions, but increasing HC and CO emissions.

The potential of an electric assisted turbocharger for a heavy-duty diesel engine has been analyzed in this work, in order to evaluate the turbo-lag reductions and the fuel consumption savings that could be obtained in an urban bus for different operating conditions. The aim of the research project was to replace the current variable geometry turbine with a fixed geometry turbine, connecting an electric machine which can be operated both as an electric motor and as an electric generator to the turbo shaft. The electric motor can be used to speed up the turbocharger during the acceleration transients and reduce the turbo-lag, while the generator can be used to recover the excess exhaust energy when the engine is operated near the rated speed, in order to produce electrical power that can be used to drive engine auxiliaries. In this way the engine efficiency can be improved and a kind of “electric turbocompounding” can be obtained.

The performance of two-stroke spark-ignition engines is greatly influenced by the scavenging process The variation of the crankcase clearance volume has here been investigated as a method for engine-load reduction. This method allows the reduction of the load without throttling or only by partial throttling with a theoretical increase of the engine efficiency. A comparison of two methods (air throttling and crankcase clearance volume variation) has therefore been carried out. The reduction of pumping work, due to the use of the variable crankcase clearance volume, has not always caused a consequent reduction of the specific fuel consumption. This is mainly due to deterioration of the scavenging process and to the occurrence of pre-ignition which occur above all at light loads.

Plug-in Hybrid Electric Vehicles (PHEVs) are one of the main technology options for reducing vehicle CO2 emissions and helping vehicle manufacturers (OEMs) to meet the CO2 targets set by different Governments from all around the world. In Europe OEMs have introduced a number of PHEV models to meet their CO2 target of 95 g/km for passenger cars set for the year 2021. Fuel consumption (FC) and CO2 emissions from PHEVs, however, strongly depend on the way they are used and on the frequency with which their battery is charged by the user. Studies have indeed revealed that in real life, with poor charging behavior from users, PHEV FC is equivalent to that of conventional vehicles, and in some cases higher, due to the increased mass and the need to keep the battery at a certain charging level.

The effects of using neat FAME (Fatty Acid Methyl Ester) in a modern small displacement passenger car diesel engine have been evaluated in this paper. In particular the effects on engine performance at full load with standard (i.e., without any special tuning) ECU calibration were analyzed, highlighting some issues in the low end torque due to the lower exhaust gas temperatures at the turbine inlet, which caused a remarkable decrease of the available boost, with a substantial decrease of the engine torque output, far beyond the expected engine derating due to the lower LHV of the fuel. However, further tests carried out after ECU recalibration, showed that the same torque levels measured under diesel operation can be obtained with neat biodiesel too, thus highlighting the potential for maintaining the same level of performance.

In this paper, a numerical and experimental assessment of post injection potential for soot emissions mitigation in an off-road diesel engine is presented, with the aim of supporting hardware selection and engine calibration processes. As a case study, a prototype off-road 3.4 liters 4-cylinder diesel engine developed by Kohler Engines was selected. In order to explore the possibility to comply with Stage V emission standards without a dedicated aftertreatment for NOx, the engine was equipped with a low pressure cooled Exhaust Gas Recirculation (EGR), allowing high EGR rates (above 30%) even at high load. To enable the exploitation of such high EGR rates with acceptable soot penalties, a two-stage turbocharger and an extremely high-pressure fuel injection system (up to 3000 bar) were adopted. Moreover, post injections events were also exploited to further mitigate soot emissions with acceptable Brake Specific Fuel Consumption (BSFC) penalties.

The DEXA Cluster consisted of three closely interlinked projects. In 2003 the DEXA Cluster concluded by demonstrating the successful development of critical technologies for Diesel exhaust particulate after-treatment, without adverse effects on NOx emissions and maintaining the fuel economy advantages of the Diesel engine well beyond the EURO IV (2000) emission standards horizon. In the present paper the most important results of the DEXA Cluster projects in the demonstration of advanced particulate control technologies, the development of a simulation toolkit for the design of diesel exhaust after-treatment systems and the development of novel particulate characterization methodologies, are presented. The motivation for the DEXA Cluster research was to increase the market competitiveness of diesel engine powertrains for passenger cars worldwide, and to accelerate the adoption of particulate control technology.

The objective of this paper is to present the results of the GT Power calibration with engine test results of the air loop system technology down selection described in the SAE Paper No. 2012-01-0831. Two specific boosting systems were identified as the preferred path forward: (1) Super-turbo with two speed Roots type supercharger, (2) Super-turbo with centrifugal mechanical compressor and CVT transmission both downstream a Fixed Geometry Turbine. The initial performance validation of the boosting hardware in the gas stand and the calibration of the GT Power model developed is described. The calibration leverages data coming from the tests on a 2 cylinder 2-stroke 0.73L diesel engine. The initial flow bench results suggested the need for a revision of the turbo matching due to the big gap in performance between predicted maps and real data. This activity was performed using Honeywell turbocharger solutions spacing from fixed geometry waste gate to variable nozzle turbo (VNT).

This paper presents an after-treatment architecture combining a close coupled NOx trap and an under floor NOx trap. Instead of simply increasing the volume of the catalyst, we propose to broaden the active temperature window by splitting the LNT along the exhaust line. In order to design this architecture, a complete 1D model of NOx trap has been developed. Validated with respect to experimental data, this model has been useful to define the two volumes of LNT, making significant savings on the test bench exploitation. However, one of the main difficulties to operate the proposed architecture is the NOx purge and sulfur poisoning management. In order to optimize the NOx and sulfur purge launches, we have developed a control strategy based on an embedded reduced LNT model. These strategies have been validated on different driving cycles, by the means of simulation and of vehicle tests using rapid prototyping tools.

The trend towards powertrain electrification is expected to grow significantly in the next future also for super-cars. The aim of this paper is therefore to assess, through numerical simulation, the impact on both fuel economy and performance of different 48 Volt mild hybrid architectures for a high-performance sport car featuring a Turbocharged Direct Injection Spark Ignition (TDISI) engine. In particular the hybrid functionalities of both a P0 (Belt Alternator Starter - BAS) and a P2 (Flywheel Alternator Starter - FAS) architecture were investigated and optimized for this kind of application through a global optimization algorithm. The analysis pointed out CO2 emission reductions potential of about 6% and 25% on NEDC, 7% and 28% on WLTC for P0 and P2 respectively. From the performance perspective, a 10% reduction in the time-to-torque was highlighted for both architectures in a load step maneuver at 2000 RPM constant speed.

In this study, different designs of intake ports for two-stroke Ultra Low Cost Gasoline Direct Injection Engine (ULC-GE) has been analyzed to conclude on best design using steady state analysis in STAR-CD. The four types of intake ports design with two cylinders, each having fourteen ports, have been studied. The basic differences in designs are horizontal inlet entry (perpendicular to cylinder axis) and vertical inlet entry (in-line with cylinder axis) having rotation of flow clockwise and anticlockwise. Each type is further differentiated in eight cases with varying distances between axis of two-cylinder as 85mm, 88mm, 91 mm, 94 mm, 97 mm, 100 mm, 105 mm and 112 mm. These designs are analyzed for four different pressure drops as 10 mbar, 50 mbar, 100 mbar and 150 mbar.

In the present work, different combustion control strategies have been experimentally tested in a heavy-duty 3.0 L Euro VI diesel engine. In particular, closed-loop pressure-based and open-loop model-based techniques, able to perform a real-time control of the center of combustion (MFB50), have been compared with the standard map-based engine calibration in order to highlight their potentialities. In the pressure-based technique, the instantaneous measurement of in-cylinder pressure signal is performed by a pressure transducer, from which the MFB50 can be directly calculated and the start of the injection of the main pulse (SOImain) is set in a closed-loop control to reach the MFB50 target, while the model-based approach exploits a heat release rate predictive model to estimate the MFB50 value and sets the corresponding SOImain in an open-loop control. The experimental campaign involved both steady-state and transient tests.

Hybrid and electric powertrains are experiencing a consistent growth in the automotive field demonstrating their effectiveness in reducing pollutant emissions especially in urban areas. Recently these technologies started to be investigated in the field of work machineries as possible solution to meet increasingly stricter regulations on pollutant emissions. The construction field was the first to recognize the benefits of a partial or total electrification of a work machinery. Nowadays, the consolidation of the technology allowed for its consistent diffusion in the more conservative agricultural field where manufacturers are struggling to meet emissions regulations without losing in terms of work performance. Tractors manufacturers are the most affected actors because of the difficulty to integrate bulky gas aftertreatment systems on board of their vehicle.

This state of art investigation report explains the limitations of Rosin-Rammler approach in comparison with breakup approach. The injection phenomenon of a commercial injector is simulated at various injection pressures, with Heptane (C7H16) in a spray bomb. It is observed that Breakup approach is better suitable in terms of correlation for spray modelling than the Rosin-Rammler approach when the injection pressures are 10 and 20 MPa, the SMD correlation shows also a good correlation at these pressures. At 4 MPa, correlation is a bit poorer, which is coherent as break-up models are best suited to high injection pressures configurations. Also, in each approach the primary dependent parameters are fine-tuned and their effects are discussed.

This paper intends to analyze the simultaneous impact of speed and acceleration on exhaust pollutant emissions. For this purpose, actual driving recording were used. Kinematic sequences were randomly selected amongst the recorded data, in order to constitute a representative set of driving conditions. For each sequence, average levels of speed and positive acceleration were calculated. Instantaneous and integrated pollutant emissions were calculated using an existing emission model, developed for calculating pollutant emissions and fuel consumption as functions of instantaneous speed and acceleration. This model is based on instantaneous emission measurements on a chassis dynamometer using actual driving cycles, over a sample of 150 European cars. Emissions of CO, CO2, HC, NOx were analyzed considering the average speed and positive acceleration, for different categories of vehicles Diesel, conventional and catalyst vehicles.

This paper is a case study from the TESSA project (French funded research program “Transfert des Efforts des Sources Solidiennes Actives”). The general frame of the work was to assess a collaborative design process between a car manufacturer and a major supplier using FE modelling and condensation of structure borne noise sources as an alternative to classic specification method for structure borne sources. Super elements from different FE commercial softwares have been used to assess the reliability of the method, the compatibility of the softwares and, most important, the relevance of applying a blocked force tensor to the component super element to predict the interior contribution of a component which is the originality of this work. The case study is an internal combustion engine cooling module (fan + shroud + exchangers) from VALEO including all assembly details (clips, decoupling elements) modelled under ABAQUS and its integration in a RENAULT Espace under NASTRAN.