Immersed Methods and Parallel Anisotropic Mesh Adaptation to Simplify the Simulation Setup using the Cloud

摘要

A full Eulerian framework for solving fluid-structure interaction (FSI) problems is proposed in this paper. It is based on a unified formulation in which the interactions are modelled by introducing an extra stress in the momentum equation. The three-field velocity, pressure and stress system obtained is solved using a stabilized finite element method. The key feature of this unified formulation is the ability to describe different kind of interactions and type of flows: laminar or turbulent flows. The fluid-structure interface is implicitly defined by a levelset function and the discontinuities are regularized with a given thickness controlled by a dynamic anisotropic mesh adaptation. The levelset function is computed using a new immersed method based on the use of non uniform rational B-splines. Indeed, the immersion of any complex object described usually by surface meshes is replaced by the direct use of the computer aided design definition keeping the quality of its analytical description. In practice, it eliminates the cost of the surface mesh generation step, increases the accuracy, reduces the complexity and allows a fluid-structure application to be easily set up on the cloud. Combined with an error estimator and parallel dynamic anisotropic mesh adaptation for detecting sharp gradients and boundary layers, it allows the creation of extremely stretched elements with shapes and orientations that match the directional features of the turbulent flow (boundary layers, flow detachments) in problems such as turbulent flows past a complex three-dimensional Fl car and rotating wind turbine. The cloud platform can be used on www.aeromines.com.