Analysis of Ethanol Spray Produced by Direct Injection into a Single Cylinder Optical Research Engine 2014-36-0345

Atomization parameters from the spray produced by a direct injection injector, operating into an engine with optical access were analyzed in this work. Parameters such as cone angle, penetration and spray geometry for determined crank angles and different rotations, with the respective variability, were evaluated for ethanol injection. Images from spray injection were captured for the specified rotation conditions for the angle and geometry analysis. For the penetration analysis, the image acquisition occurred with crank angle variation, obtaining a mean value with respect to the spray displacement of a point of maximum concentration on a specified direction. Lines were adjusted to the penetration data and the penetration rates (velocities) were evaluated through its slopes. For the cone angle and geometry study, an automatic routine in Matlab environment for image processing was used. For cone angle analysis, concentric arcs to a point considered as the origin of a polar coordinate system, and confined between the spray contours, were considered. A relation of this parameter to the distance from the injector was then studied. For the geometry analysis, data from the contours in a Cartesian coordinate system were evaluated, and linear adjustments were obtained, giving a single value for the cone angle with respect to the slope of the straight lines adjusted.