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The paper gives a short introduction to the bio-diesel mixture approach for diesel engines. The paper continues with a description of the design of a strategy for recognition of a random bio-diesel fraction, Bx, by a purely software-based sensing technique, which creates an image of the temporal combustion behavior and uses only sensors already in service for current common rail mixture preparation systems. A short description is made of a baseline approach of sensing technique based on the presence of a crank angle speed sensor. Hereafter the paper presents the introduction of several integral or Upper Level (UL) key-parameters used to enhance the precision of the Bx-detection or completely replace the original lower level combustion key-parameter set, which relates the instantaneous fraction of bio-diesel, Bx, to the engine torque.

The paper gives a short introduction to the notion of flex fuel approach for diesel engines. The paper continues with a description of a basic study of the diesel combustion process to allow the design of a strategy for recognition of a random bio-diesel fraction, Bx, by a purely software-based sensing technique, which creates an image of the temporal combustion behavior and uses only sensors already in service for current CR-mixture preparation systems. The paper concludes presenting a series of experimental verification data obtained on a large-scale series produced 1.3 liter Turbo-charged CR-rail passenger car engine.

The paper presents the background research on the physics of the droplet coalescence phenomena carried out by an interactive usage of high-level 3-D numerical simulation tools and high-level optical visualization and measurement techniques. The presentation continues with the description of a new injector atomizer plate layout, which enables a physical coalescence control of the droplet population within the entire fuel spray. Finally are presented examples of the impact on exhaust emissions of the introduction the new atomizer plate with coalescence control by engine test bed experiments (steady state low load conditions) and vehicle tests (first cold part of the FTP-cycle).

The success obtained by use of Virtual Engine Modeling (VEM) in the design and development areas of fuel injectors generated a lot of interest from production and quality engineers to dispose of a similar tool related to spray vessel measurements. To respond to stringent PL6/EURO5 requirements it was decided to develop a Virtual Spray Vessel (VSV) tool capable of predicting spray patters and perform droplet diameter analysis comparable to Phase Doppler Analysis (PDA) results. The paper describes the analogies between VEM and VSV modeling, the specific new numerical approaches to obtain spatial spray data comparable to conventional mechanical measurement techniques and to perform droplet diameter analysis comparable to PDA data. The paper concludes with a series of comparisons of simulated and experimental data.

The paper presents a short introduction on the evolution from the first generation of software based flex fuel sensor systems over the second system generation including new gasoline/ethanol optimized fuel injectors to the 3rd generation, which combines all available optimized mechanical components. It demonstrates that to meet the new emission regulations and On Board Diagnostic requirements a new highly flexible Electronic Control Unit (ECU) is needed. A detailed description of the new powerful, layered-structure ECU-family is given. The paper concludes with some illustrative experimental results obtained by combining the new ECU-family with engine-layout optimized mechanical components.

The paper presents the basic scientific analytical approach to identify the main physical parameters, which enable an optimization of several layouts for an Ethanol Cold Start (ECS) device. The main optimization criteria for the system layout are a single mixture preparation system for both cold start and hot engine handling, a short energy release time, a short start time and a possible high-precision ethanol metering system capability after start. The paper describes 3 suggested solutions. Two of the solutions are prototyped and tested on several vehicles. The paper concludes with a series of experimental data obtained on different flex engines with the new ECS-system variants. The obtained test results show good pure ethanol cold start capability for temperatures above 263 K and an excellent system temperature control of the fuel in the fuel-rail and in the injectors, which prevents the occurrence of any cavitations phenomenon.

The paper presents the main reasons for the increasing market share of vehicles with the capacity to run on random bio fuel blends. It explains the reason for which a single fuel supply system is mandatory in modern flex vehicles, even for cold start by pure ethanol fuelling The paper continues with an analytic research for the most appropriate device location and a detailed description of 3 suggested device layouts. The paper concludes by a presentation of a series of data obtained by real-time vehicle experiments at low ambient temperature conditions.

The paper presents a description of the development phases of the new third generation of “green” fuel injectors. The development objective for the new PICO-ECOlogical injector was to define a layout, which enables an optimal parameter configuration for both the mixture preparation (high flexibility to adapt different atomizer plate structures) and the manufacturing processes. It is demonstrated in which way the use of high-level numerical simulation and visualization techniques have become an integrated part of the development process. A detailed description is given of the new layout with respect to earlier versions and the advantageous new features obtained are discussed. Test results obtained by the new 3rd-generation injector layout are presented. The impact of the improved dynamic response capability is explained and experimental data at both engine test rig and vehicle FTP-cycle conditions are reported and discussed.

On the basis of the large amount of know-how accumulated in the field of automotive ethanol SI-engine fuelling in Brazil, it seemed appropriate to continue and set a new milestone in the usage of ethanol fuel. The paper presents the preliminary study made to enable the transfer of the ethanol technology to a 5.9-liter 4-cylinder boxer aircraft engine. The study describes the steps made to define the optimal parameter configuration for the transfer of the fuel system packaging, the fuel injector layout, the engine control unit (ECU) and the legislative redundancy requirements for aviation applications. The paper illustrates the use of numerical simulation techniques and special visualization approaches necessary to understand the physical phenomena of mixture preparation (spray atomization and momentum). Two different layouts are presented and discussed and a certain number of experimental results obtained with the retained solution are presented and discussed.

The paper describes the optimization to match the Brazilian market requirements for a Flex-Vehicle of the intake system and in particular the fuel injectors of a small displacement (1.6 l) 8 valves passenger car engine. The imposed target was to find a compromise for the hardware components related to the mixture preparation process, which optimize their performance with respect to a gasoline with a random content (from 0 to 100 %) of ethanol. The analytical optimization process is performed by use of a 3-D numerical virtual engine in which can be studied the physical phenomena of spray atomization, vaporization and momentum fluctuations from different injector atomizer layouts. The different atomizer layouts as well as several vaporization enhancement approaches are rated with respect to a baseline configuration on the virtual engine. The paper presents the results obtained by highest rated solutions, which were manufactured as prototypes and tested on the real engine.

The first part of the paper gives an overview of the results obtained with European GDI-powered vehicles launched on the market. Thereafter, a discussion of in-vehicle limitations due to the exhaust gas after-treatment system requirements is given. The paper continues with a description of the current development status of European lean stratified direct injection system layouts. A detailed presentation is made of the mixture preparation system key components, basic control algorithms and the necessary new high-level experimental and analytical development tools. Particularly the topic of the multi-purpose use of 3-D numerical simulation is addressed both in the development and the engine control strategy calibration phases. The development of a small 1.6 liter lean stratified engine project is taken as example to demonstrate the dual application capability of the 3D simulation tool.