Joint Seminar: Civil Engineering and Open Science series

The Civil Engineering Institute, in collaboration with ENAC Open Science and the Open Science office, are happy to present:

The X-MESH method for capturing interfaces
by Prof. Jean-François Remacle, from UCLouvain  
 
In this presentation, we develop an innovative approach - X-MESH - to overcome a major difficulty associated with numerical simulation in engineering: we aim to provide a revolutionary way to track physical interfaces in finite element simulations. The idea is to use so-called extreme mesh deformations. This new approach should allow low computational cost simulations as well as high robustness and accuracy. X-MESH is designed to avoid the pitfalls of current ALE methods by allowing topological changes on fixed mesh.
The key idea of X-MESH is to allow elements to deform until they reach a zero measure. For example, a triangle can deform into an edge or even a point. This idea is rather extreme and completely revisits the interaction between the meshing community and the computational community, which for decades have been trying to interact through beautiful meshes.
In this talk, we will focus on both the mathematical issues related to the use of zero-measure elements and the X-MESH resolution scheme.Several applications will be targeted: the Stefan model of phase change, two-phase flows and contact between deformable solids.

The seminar will be followed by an open discussion on the benefits and obstacles of developing open science projects, and how to rethink the future of research in a more collaborative way. Food will be provided following the seminar, to encourage networking and get to know the speaker!

About the speaker
 
After his Engineering Degree at the University of Liege in Belgium in 1992, Jean-François Remacle obtained in 1997 a Ph.D. from the same University. He then spent two years at the Ecole Polytechnique de Montréal as a post-doctoral fellow of Prof. F. Trochu, followed by three years at Rensselaer Polytechnic Institute in the research team of Prof. M. Shephard (one year as research associate followed by two years as research assistant professor). It was during his stay at Rensselaer that Pr. Remacle started to work closely with Mark Shephard on mesh generation. Pr. Shephard’s seminal work on mesh generation is one of the most important contributions ever. It was also during that stay that Pr. Remacle started the development of Gmsh, the open source mesh generator. After these five years in Northern America, Jean-François Remacle joined the Université catholique de Louvain in 2002 as an assistant Professor. He then became Associate Professor in 2005 and Full Professor in 2012. In the following years of his return to Europe, Pr. Remacle dedicated a large part of his research to mesh generation.
 
Since 2002, Pr. Remacle and his colleague Pr. C. Geuzaine from the University of Liège have continued the development of Gmsh (www.gmsh.info). Gmsh was initially released as an open source in 2003 under the GNU General Public Licence (GPL). In 2009, a paper was published in the International Journal for Numerical Methods in Engineering (IJNME) that describes original features of Gmsh [GR09]. This paper is the most cited paper of IJNME in the last 3 years (https://onlinelibrary.wiley.com/journal/10970207). Gmsh was awarded a free software prize at the “trophées du libre” in 2009 . The size of Gmsh’s user community is now of over 8,000 regular users, including engineers of major European industries like Siemens, Dassault, EDF, Airbus or Snecma. Three Gmsh workshops have been organized, the last one in 2017.
 
In 2015, Pr. Remacle received an ERC Advanced Grant (www.hextreme.eu) with two major subjects: fast mesh generation and hexahedral mesh generation. Several breakthroughs have been achieved in HEXTREME, the three most significative ones being the developement of the fastest tetrahedral mesh generator, the use of Ginzburg Landau theory for generating quad meshes, and the development of an algorithm to build combinatorial hexahedral meshes whose boundary facets exactly match a given quadrangulation of the topological sphere.
 
In 2022,  Pr. Remacle received an ERC SYNERGY Grant together with Pr. Moës (Ecole Centrale de Nantes).
 
Since 2016, the papers co-authored by Jean-François Remacle received over 6600 citations (Source: Google Scholar). It is interesting to note that these citations are not only related to mesh generation but to a wide a spectrum of computational fields: computational fluid dynamics, ocean modeling, computational material science, fracture mechanics, biomechanics, scientific visualization, high performance computing.
 
In parallel to the fundamental developments of the mesh generation, Pr. Remacle has been actively involved in collaborative projects. The fruitful interactions that he had with engineers of major European consortia (Airbus, Siemens, Dassault) have convinced him of the great interest of the European industry for new  developments in mesh generation for computational mechanics.