Moving mesh strategy for simulating sliding and rolling dynamics of droplets on inclined surfaces with finite element method

[[abstract]]Finite element method (FEM) moving mesh strategy for simulating dynamics of droplets on inclined surfaces is designed within arbitrary Lagrangian Eulerian (ALE) framework. Depending on the physical and chemical properties of the fluid and the supporting surface, resulting droplet dynamics can exhibit sliding and/or rolling regimes. Exploiting the full potential of the ALE framework, moving mesh strategy designed in this work is capable of tracking the droplet evolution regardless of the flow regime and without the need for frequent mesh adaptation. Additional attention is invested into the discrete energy balance: possible sources of spurious energy due to the mesh motion are identified and investigated. The overall strategy exhibits a good tradeoff between the stability and efficiency, and demonstrates the ability to perform long-time simulations. The capabilities of the proposed strategy are demonstrated on a couple of fairly complex (3D) scenarios motivated by the industrial applications. In particular, droplet dynamics is simulated for the case of inclined and heterogeneous supporting surfaces, which are designed with the aim to manipulate the droplet motion. Complex dynamics, including sliding, rolling and change in movement direction and wetting area, is successfully captured by the numerical simulation