### Description

Talks by users and perspective users of the deal.II library

Giuseppe Pitton
(SISSA)

7/23/18, 11:00 AM

Users' track

Contributed talks

In this talk I will recall some basic notions of augmented and deflated Krylov space methods for the iterative solution of linear systems.
Then I will discuss a few strategies to apply these techniques to the solution of linear systems coming from nonlinear scalar convection-diffusion equations.
A simple back-of-the-envelope analysis allows to argue that in some cases it may be convenient to...

Mr
Sean McGovern
(Forschungszentrum Juelich)

7/23/18, 11:20 AM

Users' track

Contributed talks

Given the context of distributed parallelism, the purpose of this contribution is to consider a solution procedure to the classical Stefan phase change problem, an example of a free boundary problem. In the Stefan problem, the interface between water and ice moves through a domain as the ice melts due to a heat source. As an example of an interface problem, we choose to apply the level set...

Jiaxin Wang
(SISSA)

7/23/18, 11:40 AM

Users' track

Contributed talks

Cosmic ray propagation in fluid approach can be described as a PDE system,
which lives in 6D spatial-spectral space.
In our project, we attempt to build up a solver for such a system,
by combining independent triangulation in two domains (spatial and spectral).
In this talk, I will present why and how we build this framework with Kronecker
product.

Dario Abbondanza
(Sapienza University of Rome)

7/24/18, 11:00 AM

Users' track

Contributed talks

It has been recently shown that a Diffuse Interface model is able to fully describe the dynamics of multiphase flows. In particular, the possibility of deriving a set of equations addressing the dynamic of the entire domain of simulation, makes it ideal to describe phenomena such as vapor bubble dynamics in a surrounding liquid. The model is able to capture surface tension effects, phase...

Mr
Benjamin Brands
(Friedrich-Alexander-Universität Erlangen-Nürnberg)

7/24/18, 11:20 AM

Users' track

Contributed talks

The mechanical response of magnetorheological composites is highly affected by an applied magnetic field. Since a generally valid constitutive law does not exist for such heterogeneous materials, multiscale techniques like computational homogenisation are commonly used to approximate effective macroscopic properties. In our approach the macroscopic quantities at a material point of a...

Dr
Nicola Giuliani
(SISSA)

7/24/18, 11:40 AM

Users' track

Contributed talks

During the last 8 years the mathLab laboratory at SISSA has analysed the swimming mechanisms of micro-organisms (unicellular beings as protists, algae or bacteria) both from a theoretical and an experimental point view. In this work we present a way to derive an accurate and reliable numerical setting for the resolution of general swimming mechanism. Such a framework can be seen as a numerical...

Mr
Giovanni Alzetta
(SISSA)

7/25/18, 11:00 AM

Users' track

Contributed talks

I am beginning this talk with a quick recall of the general difficulties faced when using multiple grids on a distributed memory setting and some possible solutions.
As a model problem I am presenting briefly the Lagrange-multiplier method of step-60, where a harmonic equation with values prescribed at the boundary and on a sub-domain is solved, with a particular focus on the coupling matrix...

Michal Wichrowski
(Instytut Podstawowych Problemów Techniki)

7/25/18, 11:20 AM

Users' track

Contributed talks

The goal of my work is to develop robust scalable solver for linear system arising from finite element discretization of Stokes problem with strongly variable viscosity. Such linear systems appear in fluid-structure problems.
Symmetric positive define problems with discontinuous coefficient can be solved effectively by multigrid preconditioned Krylov subspace methods. Here we extend this...

Julius Witte
(Heidelberg University)

7/25/18, 11:40 AM

Users' track

Invited talks

The goal of the ExaDG project is to provide efficient finite element solvers relying on `deal.II`'s `MatrixFree` framework based on higher order DG methods. However, the matrix-free operators restrict the choice of preconditioners. A powerful tool is offered by a geometric multigrid algorithm having a favorable linear complexity. The quality of multigrid preconditioners is crucially dependent...

Dr
Andrea Mola
(SISSA)

7/26/18, 11:00 AM

Users' track

Contributed talks

To exploit the automated mesh generation and adaptive refinement capabilities offered by deal.II, the user must provide its program with a suitable description of the domain geometry. In particular, it is fundamental that the geometries of boundary and internal surfaces are available to the triangulation so that the nodes generated across each mesh refinement are placed onto such surfaces, in...