Complex transition pathways in boiling and cavitation Version of Record - Zenodo Deposit

This is the Version of Record (VoR) of the following article: Gallo, M., Occhioni, F., Magaletti, F., & Casciola, C.M. (2025). Complex transition pathways in boiling and cavitation. Journal of Fluid Mechanics, 1019, A53. https://doi.org/10.1017/jfm.2025.10591 This work combines Navier–Stokes–Korteweg dynamics and rare event techniques to investigate the transition pathways and times of vapour bubble nucleation in metastable liquids under homogeneous and heterogeneous conditions. The nucleation pathways deviate from classical theory, showing that bubble volume alone is an inadequate reaction coordinate. The nucleation mechanism is driven by long-wavelength fluctuations with densities slightly different from the metastable liquid. A new strategy is proposed to evaluate the typical nucleation times by inferring the diffusion coefficients from hydrodynamics. The methodology is validated against state-of-the-art nucleation theories in homogeneous conditions, revealing non-trivial, significant effects of surface wettability on heterogeneous nucleation. Notably, homogeneous nucleation is detected at moderate hydrophilic wettabilities despite the presence of a wall, an effect not captured by classical theories but consistent with atomistic simulations. Hydrophobic surfaces, instead, anticipate the spinodal. The proposed approach is fairly general and can be easily extended to any real fluid provided the equation of state is available, paving the way to model complex nucleation problems in real systems. Funding: Funded by the European Union. Views and opinions expressed are, however, those of the authors only and do not necessarily reflect those of the European Union or the European Research Council Executive Agency. Neither the European Union nor the granting authority can be held responsible for them. This work is supported by an ERC grant (ERC-STG E-Nucl. Grant agreement ID: 101163330). Data availability: The final data supporting this research are publicly available at https://doi.org/10.5281/zenodo.16887148.