New Jersey Institute of Technology
Department of Mathematical Sciences

Capstone Laboratory

Study of Impact of Molten Wax Droplets on Substrates

Instructor: Shahriar Afkhami

This capstone project was dedicated to the solidification and impact of a wax drop impacting a solid surface. In a first part, we established a 1D solidification model, derived from the Stefan problem and energetic arguments, that aimed at predicting the experimental observations. We then carried out experiments to study the parameters that determined the dynamics of droplets of paraffin wax impinging and freezing on a metal and a glass surface. The impacts were photographed and the spreading of the splat formed after freezing was measured. Photographs showed liquid wax droplet recoiling in the center followed by the solidification. By comparing to the simple model, we found that the early stage solidification did not affect the drop impact. A simple model was then used to predict the number of azimuthal instabilities that grew at the rim of the spreading drops upon impact. Future study will consider the contact line effects.

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