ディーゼル噴霧粒子の挙動に関する研究

抄録

This study was performed to clarify the mechanism of mixture formation at peripheral area of diesel spray with PIV technique. Two dimensional cross-sectional photographs of diesel spray were taken with double pulse laser sheet. Local fuel spray particles were analyzed with an auto-correlation method and velocity vector and vorticity of the fuel spray particle were obtained. The vortex number increased and vorticity scale became smaller and its value grew higher with both smaller injection nozzle diameter and higher fuel injection velocity. With this injection condition, the mixing of fuel spray with ambient gas seems to be improved and the turbulence is expected to increase in the regions of higher vortex number, higher vorticity and smaller vorticity scale. Based on above results, the branch-like structure of diesel fuel spray was considered to be caused by vortices which formed in the shear layer between the spray and the ambient gas.