Dynamics of entrapped air bubble during impact of high-velocity molten droplet on a solid substrate

Digvijay Singh
Indian Institute of Technology Kanpur Kanpur, Uttar Pradesh, 208016, India

Rajesh Kumar Shukla
Indian Institute of Technology Kanpur Kanpur, Uttar Pradesh, 208016, India

Arvind Kumar
Dept. of Mechanical Engineering, Indian Institute of Technology Kanpur Kanpur, Uttar Pradesh, 208016, India

DOI: 10.1615/IHMTC-2017.1360
pages 981-985

Abstract

In the present study, a numerical model has been developed to investigate the dynamics of the air bubble which has been formed during the high-speed impact of a molten droplet on the cold substrate. In the model impact, spreading and solidification of a molten droplet on a flat surface including the effect of the surrounding air have been considered. The volume of fluid surface tracking method (VOF) coupled with the solidification model within a one-domain continuum formulation is utilized to model the transient flow during the droplet impact. Model completely captured the air bubble formed. It is found that initially a thin circular film of air was trapped at the centre of the droplet which further grew into a large air bubble that eventually breaking through the upper surface of the droplet and creates a hole in the centre portion.