Mixture Preparation Optimization by CFD of a Flex-Vehicle (Gasoline/Ethanol) Intake System Layout

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.