Abstract
Quick mixing of fuel and air is one of the most essential factors to improve combustion and emissions in diesel engines. This paper investigates diffusion structure of sprays injected in engines using entropy analysis. The method allows the analysis of heterogeneity degree and diffusion intensity in pictures. Introducing laser sheet in an engine, cross-sectional images of the spray were obtained, and diffusion structures were compared for the swirl ratios. The result of the analysis shows that the swirl has an effect of changing fuel distribution but it does not have effect of increasing local diffusion coefficients, rather the medium scale diffusion intensity decreases by the swirl.
