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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 a sensing technique using a crank angle speed sensor. Hereafter the paper continues by the introduction of several integral or Upper Level (UL) key-parameters applied 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 concludes presenting a series of experimental verification data obtained on a large-scale series produced 1.3 liter Turbo CR-rail passenger car engine.

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 common rail mixture preparation systems. A description is made of two different approaches to software- based sensing techniques, one based on the presence of a crank angle speed sensor and the other on the presence of a lambda sensor in the exhaust system. The principles of the associated software flow diagrams embedded in the engine control unit are also explained. The paper concludes presenting a series of experimental verification data obtained on a large-scale series produced 1.3 liter turbo-charged common rail passenger car engine.

This paper intends to describe spray predictions using CFD technologies for spray formation and evolution on fuel blend. Spray formation was simulated in ANSYS CFX using a Lagrangian model. The primary breakup model used in this study is a variation of the well-known BLOB method. The Cascade Atomization Breakup (CAB) and Modified Cascade Atomization Breakup (MCAB) models for secondary breakup were used. Simulations using different Rosin Rammler distributions were carried out. N-Heptane was used as reference fuel for experimental tests. A high degree of consistency between experimental data and numerical analysis for spray propagation characteristics was found. The methodology has been developed on Heptanes, aiming to extend the methodology to other fuels, i.e. ethanol.

The paper presents the background physics of droplet coalescence phenomena and the basic research carried on the topic by interactive use 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 possess 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 patterns and perform droplet diameter analysis comparable to real-time Phase Doppler Analysis (PDA) results. The paper describes the analogies between VEM and VSV modeling and 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 from virtual and real-time measurement vessels.

The paper presents a study made to define the optimal parameter configuration, which enables the mixture preparation, and ignition systems to perform a low-temperature engine start by pure ethanol fuelling without misfiring or failure. A numerical virtual engine, simulating the behavior of a real small displacement 8 valves passenger car engine, is set up to describe and understand the physical phenomena of mixture preparation, spatial and temporal in-cylinder mixture distribution and the ignition/combustion events. The complex phenomena, which govern the gas flow patterns and mixture formation in the intake port and the combustion chamber are particularly analyzed during low-temperature engine cranking. Furthermore is discussed the influence of open and closed valve injection modes.

The fossil fuels will still be the energy source used in the mobility industry by the next generations. In several countries, however, already the initiative exists for the use of alternatives energy from biomass, what demands the development of new technologies for the emissions and fuel consumption reduction. That is a constant challenge for world wide research and development centers. Brazil, pioneer in the mass production of alcohol vehicles in the 80'decade, blunts in the last two years with a new large scale program, a new Flexfuel vehicles generation that will crosses 60% sales in the end of 2005. These vehicles use in the same engine, any mixture in any proportion of the ethanol or gasoline.