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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 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.

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.