2022/02/15 by Chengxi Zhao, Jingbang Liu, Zhao, Chengxi +5 · 2 citations
Engineering · Physics and Astronomy · #FOS: Physical sciences #Fluid Dynamics (physics.flu-dyn) #Fluid Dynamics and Heat Transfer #Fluid Dynamics and Thin Films #Lattice Boltzmann Simulation Studies #physics.flu-dyn
paper · pdf · doi:10.48550/arxiv.2202.07410
arxiv created 2022/02/15 · openalex publication_date 2022/02/15 · arxiv updated 2022/02/16 · openalex created_date 2022/08/08 · openalex updated_date 2026/07/28
The effects of thermal fluctuations on nanoscale flows are captured by a numerical scheme that is underpinned by fluctuating hydrodynamics. A stochastic lubrication equation (SLE) is solved on non-uniform adaptive grids to study a series of nanoscale thin-film flows. The Fornberg scheme is used for high-resolution spatial discretisation and a fully-implicit time-marching scheme is designed for numerical stability. The accuracy of the numerical method is verified against theoretical results for thermal capillary waves during the linear stage of their development. The framework is then used to study the nonlinear behaviour of three bounded thin-film flows: (i) droplet spreading, where new power laws are derived; (ii) droplet coalescence, where molecular dynamics results are reproduced by the SLE at a fraction of the computational cost and it is discovered that thermal fluctuations decelerate the process, in contrast to previously investigated phenomena; and (iii) thin-film rupture, where, in the regime considered, disjoining pressure dominates the final stages of rupture.