An experimental investigation of droplet morphology in swirl flow

The interaction of a droplet with swirling airstream is investigated experimentally using shadowgraphy and particle image velocimetry techniques. In swirl flow, the experiences oppose-flow, cross-flow co-flow conditions depending on its ejection location, velocity strength, which results in distinct morphologies as compared straight airflow situation. We observe new breakup phenomenon, termed ‘retracting bag breakup’, encounters differential flow field created by wake swirler's vanes central recirculation zone airflow. A regime map demarcating various modes, such no breakup, vibrational retracting presented for different sets dimensionless parameters influencing morphology trajectory. contrast to promotes development Rayleigh–Taylor instability, enhancing stretching factor deformation process, resulting larger number fingers droplet's surface. order gain physical insight, modified theoretical analysis based instability proposed flow. experimental behaviour phenomena can be determined modifying model.