Computationally Efficient Thermomechanical Contact Models for Creeping Flows

Fluid flow at low Reynold's numbers is referred to as viscous, creeping or Stokes flow. Thermomechanical contact between solid components and creeping flows plays an important role in many technical and industrial applications like metal casting, polymer molding and additive manufacturing. Accurate and efficient numerical simulation enhances the understanding of these processes and helps to improve their accuracy. While dynamic fluid flow simulations with classical volumetric finite element (FE) analysis cause a large computational effort, a very efficient method is developed in this project: An FE surface formulation is coupled with a boundary element (BE) formulation for Stokes flow to model mechanical contact between creeping flows and solids. Since volume discretization is avoided for the BE method and the FE surface formulation, the computational as well as the meshing effort of the entire method is highly reduced. The thermal behavior of the fluid flow is also modeled very efficiently: The BE method is used to determine the heat conduction within the fluid, while a stochastic approach is developed to determine the current surface wetting and the resulting heat transfer at the solid-liquid interface in dependence of surface, material and process parameters.