Abstract
Quick mixing of fuel and air is one of the most essential factors to improve combustion and emissions in diesel engines. The paper investigates local diffusion phenomena with focusing on scales of the diffusion in turbulent jets. Analysis was made with entropic concept proposed in the previous paper; it analyses homogeneity degree and scales of the heterogeneity in a picture. The result shows the effectiveness of the entropic analysis method for identification of scales of heterogeneity and diffusion intensity. The result of the experiment shows that the diffusion intensity is the highest at the vicinity of the nozzle exit, and the heterogeneity scale is the smallest. The heterogeneity scale increases gradually along the spray axis towards downstream, with containing smaller scales inside of the large clouds. In the downstream region, small-scale structure diffuses and becomes unclear, while large scale structure remains clearly.
