Computational Engineering

The focus of this Computational Engineering Workshop was on the mathematical foundation of state-of-the-art and emerging finite element methods in engineering analysis. The 52 participants included mathematicians and engineers with shared interest on discontinuous Galerkin or Petrov-Galerkin methods and other generalized nonconforming or mixed finite element methods

Least-Squares FEM: Literature Review

During the last years the interest in least squares finite element methods (LSFEM) has grown continuously. Least squares finite element methods offer some advantages over the widely used Galerkin variational principle. One reason is the ability to cope with first order differential operators without special treatment as required by the Galerkin FEM. The other reason comes from the numerical point of view, where the LSFEM leads to symmetric positive definite matrices which can be solved very efficiently under some conditions. This report gives an overview about the recent literature which appeared in the field of least squares finite element methods and summarises the essential results and facts about the LSFEM.Während der letzten Jahre hat das Interesse an Least Squares Finite Element Methoden (LSFEM) stetig zugenommen. Least Squares Finite Element Methoden bieten einige Vorteile gegenüber dem etablierten Galerkin Variationsansatz. So können Differentialoperatoren erster Ordnung ohne besondere numerische Techniken, wie z.B. Stabilisierung, direkt behandelt werden. Ein anderer Grund für den Einsatz der LSFEM liegt in den entstehenden algebraischen Gleichungssystemen, die immer symmetrisch positiv definit sind und unter bestimmten Vorraussetzungen eine effiziente Lösung ermöglichen.Dieser Bericht gibt einen Überblick über die aktuelle Literatur zur LSFEM und faßt die entscheidenden Ergebnisse zusammen

Discontinuous Galerkin Method Applied to Navier-Stokes Equations

Discontinuous Galerkin (DG) finite element methods are becoming important techniques for the computational solution of many real-world problems describe by differential equations. They combine many attractive features of the finite element and the finite volume methods. These methods have been successfully applied to many important PDEs arising from a wide range of applications. DG methods are highly accurate numerical methods and have considerable advantages over the classical numerical methods available in the literature. DG methods can easily handle meshes with hanging nodes, elements of various types and shapes, and local spaces of different orders. Furthermore, DG methods provide accurate and efficient simulation of physical and engineering problems, especially in settings where the solutions exhibit poor regularity. For these reasons, they have attracted the attention of many researchers working in diverse areas, from computational fluid dynamics, solid mechanics and optimal control, to finance, biology and geology. In this talk, we give an overview of the main features of DG methods and their extensions. We first introduce the DG method for solving classical differential equations. Then, we extend the methods to other equations such as Navier-Stokes equations. The Navier-Stokes equations are useful because they describe the physics of many phenomena of scientific and engineering interest. They may be used to model the weather, ocean currents, water flow in a pipe and air flow around a wing

FEMPAR: an object-oriented parallel finite element framework

FEMPAR is an open source object oriented Fortran200X scientific software library for the high-performance scalable simulation of complex multiphysics problems governed by partial differential equations at large scales, by exploiting state-of-the-art supercomputing resources. It is a highly modularized, flexible, and extensible library, that provides a set of modules that can be combined to carry out the different steps of the simulation pipeline. FEMPAR includes a rich set of algorithms for the discretization step, namely (arbitrary-order) grad, div, and curl-conforming finite element methods, discontinuous Galerkin methods, B-splines, and unfitted finite element techniques on cut cells, combined with h-adaptivity. The linear solver module relies on state-of-the-art bulk-asynchronous implementations of multilevel domain decomposition solvers for the different discretization alternatives and block-preconditioning techniques for multiphysics problems. FEMPAR is a framework that provides users with out-of-the-box state-of-the-art discretization techniques and highly scalable solvers for the simulation of complex applications, hiding the dramatic complexity of the underlying algorithms. But it is also a framework for researchers that want to experience with new algorithms and solvers, by providing a highly extensible framework. In this work, the first one in a series of articles about FEMPAR, we provide a detailed introduction to the software abstractions used in the discretization module and the related geometrical module. We also provide some ingredients about the assembly of linear systems arising from finite element discretizations, but the software design of complex scalable multilevel solvers is postponed to a subsequent work.Peer ReviewedPostprint (published version