Sheared capillary waves on nanometer scales

在大体积流体中，流体动力学的Navier-Stokes方程被证明是适用于纳米尺度的。然而，最近的研究表明，衬底电势和热噪声的相互作用可以在横向更大的尺度上导致性质不同的行为，最高可达微米。基于流体动力学方程的随机版本，该建议旨在建立界面流体流动的理论模型，其中最近的实验表明热噪声对流体流动的影响：(I)剪切胶体分散中的液滴合并和界面流动；(Ii)纳米尺度上的毛细管波；(Iii)流体在薄膜中的流动。我们将应用非线性随机流体动力学方程和含时密度泛函理论，并结合几何技术，如法坐标。我们期望阐明(I)热毛细波在合并事件中的作用；(Ii)色散关系和衰减因子对分子相互作用的依赖；(Iii)实验和模拟之间的差异--最近在薄膜流动中发现的。

In bulk fluids hydrodynamic Navier-Stokes equations are proven to be valid down to the nanometer scale. However, at interfaces it was shown recently that the interplay of substrate potentials and thermal noise can lead to qualitative different behaviour on laterally much larger scales up to microns. Based on a stochastic version of the hydrodynamic equations this proposal aims at the theoretical modelling of fluid flow at interfaces, where recent experiments indicate an influence of thermal noise on fluid flow: (i) droplet coalescence and interfacial flow in sheared colloidal dispersions; (ii) capillary waves on a nanometer scale; (iii) fluid flow in thin liquid films. We will apply non-linear stochastic hydrodynamic equations and time-dependent density functional theory, in combinations with geometric techniques such as normal coordinates. We expect to elucidate (i) the role of thermal capillary waves on the coalescence event; (ii) the dependence of dispersion relations and damping factors on molecular interactions; (iii) the discrepancies between experiments and simulations - discovered recently in thin film flow.