In this paper we present a new Eulerian finite element method for the discretization of scalar partial differential equations on evolving surfaces. In this method we use the restriction of standard space-time finite element spaces on a fixed bulk mesh to the space-time surface. The structure of the method is such that it naturally fits to a level set representation of the evolving surface. The higher order version of the method is based on a space-time variant of a mesh deformation that has been developed in the literature for stationary surfaces. The discretization method that we present is of (optimal) higher order accuracy for smoothly varying surfaces with sufficiently smooth solutions. Without any modifications the method can be used for the discretization of problems with topological singularities. A numerical study demonstrates both the higher order accuracy for smooth cases and the robustness with respect to toplogical singularities.
翻译:在本文中,我们提出了一个新的Eularian 有限元素方法,用于对不断演变的表面的标度部分差异方程式进行离散化。在这种方法中,我们使用对固定的成块网格与时空表面标准时空有限元素空间的限制。该方法的结构使该方法自然符合不断变化的表面的定级表示。该方法的较高顺序版本基于文文献中为固定表面开发的网状变形的时空变异变量。我们采用的离散法是(最优的)对平滑的、有足够顺利溶解的平滑的表面的平整。在不作任何修改的情况下,该方法可用于与表层特性问题分解。一项数字研究显示,光滑的个案具有较高的顺序准确性,以及相对于表层特性的稳健性。