Analysis of Evaporation Process of Non-Axisymmetric Wall-Impinging Spray by Means of Laser Absorption Scattering Technique

An evaporation process plays an important role on the combustion and emission formation processes in a direct injection (D. I.) gasoline engines. An experimental study was conducted on the evaporation process of the non-axisymmetric wall-impinging spray injected by the hole type injector for a D. I. gasoline engine. For the quantitative measurement of the vapor of the non-axisymmetric spray, the image processing technique using the Laser Absorption Scattering (LAS) principle was newly developed. The total amount of fuel vapor in the whole spray was obtained from the optical thickness image of the vapor and the Lambert Beer's law. The amount of fuel vapor in the wall-impinging spray is decreased compared with the free spray. In addition, the amount of fuel vapor is decreased as the distance between nozzle tip and the impingement wall is decreased.