・Title：Clustering Dynamics of Fuel Spray Droplets in Homogeneous Isotropic Turbulence

・Speaker’s Name and Affiliation：Prof. Srikrishna Sahu, Indian Institute of Technology Madras (IIT Madras), India

（Dr Srikrishna Sahu is a Professor in the Department of Mechanical Engineering at Indian Institute of Technology Madras (IITM). He received his PhD from Imperial College London, UK, in 2011. He worked as a Post-Doctoral Research Fellow at Imperial College for two years before joining IIT Madras in 2013.  His research focuses on the development and application of advanced optical diagnostics for multiphase flow and combustion studies. His primary areas of interest include liquid atomization, spray dynamics and combustion, particle–turbulence interactions, multicomponent droplet evaporation and combustion, and spray–wall interaction.）

・Time：Tue., May 26, 11:30–12:30

・Venue：A3-131, Faculty of Engineering, Hiroshima University
・Abstract：In this lecture, I will present our ongoing research on how air turbulence affects the collective vaporization of fuel droplet clusters. Experiments are conducted in a box-of-turbulence facility, where acetone droplets are introduced into homogeneous isotropic turbulence. Droplet clusters are identified using Voronoi analysis of PIV images, and droplet sizes are measured using the ILIDS technique. Using cluster length scale, inter-droplet spacing, and droplet size, the group number G is evaluated for individual clusters. The results show that droplet clusters span a wide range of turbulence scales, with G varying from about 0.1 to 10, indicating different group evaporation modes. Higher turbulence intensity promotes stronger clustering and larger clusters. Small-scale clusters show nearly unchanged evaporation rates, whereas large-scale clusters exhibit reduced evaporation rates at higher turbulence intensity, highlighting stronger collective vaporization effects.