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arXiv · 2401.17762

Spreading and engulfment of a viscoelastic film onto a Newtonian droplet

Chunheng Zhao·Taehun Lee·Andreas Carlson
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Abstract

We use the conservative phase-field lattice Boltzmann method to investigate the dynamics when a Newtonian droplet comes in contact with an immiscible viscoelastic liquid film. The dynamics of the three liquid phases are explored through numerical simulations, with a focus on illustrating the contact line dynamics and the viscoelastic effects described by the Oldroyd-B model. The droplet dynamics are contrasted with the case of a Newtonian fluid film. The simulations demonstrate that when the film is viscoelastic, the droplet dynamics become insensitive to the film thickness when the polymer viscosity and relaxation time are large. A viscoelastic ridge forms at the moving contact line, which evolves with a power-law dependence on time. By rescaling the interface profile of the ridge using its height and width, it appears to collapse onto a similar shape. Our findings reveal a strong correlation between the viscoelastic stress and the interface shape near the contact line.

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Chunheng Zhao, Taehun Lee, Andreas Carlson. 2024-01-31. Spreading and engulfment of a viscoelastic film onto a Newtonian droplet. https://arxiv.org/abs/2401.17762

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