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arXiv · 2509.01495

Laser-driven droplet deformation at low Weber numbers

M. Kharbedia·H. L. França·H. K. Schubert·D. J. Engels·M. Jalaal·O. O. Versolato
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Abstract

We investigate droplet deformation following laser-pulse impact at low Weber numbers (We ~ 0.1-100). Droplet dynamics can be characterized by two key parameters: the impact We number and the width, W, of the distribution of the impact force over the droplet surface. By varying laser pulse energy, our experiments traverse a phase space comprising (I) droplet oscillation, (II) breakup, or (III) sheet formation. Numerical simulations complement the experiments by determining the pressure width and by allowing We and W to be varied independently, despite their correlation in the experiments. A single phase diagram, integrating observations from both experiments and simulations, demonstrates that all phenomena can be explained by a single parameter: the deformation Weber number Wed=f(We, W) that is based on the initial radial expansion speed of the droplet, following impact. The resulting phase diagram separates (I) droplet oscillation for Wed<5, from (II) breakup for 5 60.

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M. Kharbedia, H. L. França, H. K. Schubert, D. J. Engels, M. Jalaal, O. O. Versolato. 2025-09-01. Laser-driven droplet deformation at low Weber numbers. https://arxiv.org/abs/2509.01495

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