We are pleased to announce a mini-workshop on geology and meshing, April 1st, 2016.
New numerical schemes to simulate hydrodynamic, geomechanical and seismological processes have a great potential to handle geometrically complex geological features. Unlocking this potential calls for appropriate meshing algorithms which can adapt to geological heterogeneities while meeting numerical requirements. On the occasion of the PhD defense of Arnaud Botella, this workshop will provide opportunities to discuss about recent advances, trends and challenges in this field.
Morning, Salle Gallé, Présidence UL, Campus Brabois (map):
|9h30||Jean Virieux (Institut des Sciences de la Terre, Université de Grenoble)||Les modes de représentation des milieux pour l'imagerie et pour la modélisation (Medium representations for imaging and modeling)|
|10h||Adrien Loseille (GAMMA 3, INRIA Rocquencourt)||Sur un opérateur unique et robuste de modification de maillages et application à la génération de maillages adaptatifs (On a unique and robust operator for mesh editing - Application to adaptive mesh generation)|
|10h45||Jean-Francois Remacle (École Polytechnique de Louvain)||Fine grain Multi-threaded mesh generation|
|11h15||Géraldine Pichot (SERENA, INRIA Paris)||Problématiques de maillages de réseaux de fractures aléatoire (Meshing random discrete fracture networks)|
Afternoon, Amphi G, Ecole Nationale Supérieure de Géologie, Campus Brabois
14h30: PhD defense of Arnaud Botella: Génération de maillages non structurés volumiques de modèles géologicaues pour la simulation de phénomènes physiques (Unstructured volumetric meshing of geological models for physical phenomenon simulations).
Abstract: The main goals of geomodeling are to represent and understand the subsurface. The geological structures have an important role for understanding and predicting its physical behavior.
We defined a geological model as a set of structures and their connections. The meshes are numerical supports to solve the equations modeling the subsurface physics. So it is important to build a mesh representing a geological model to take into account the impact of these structures on the subsurface phenomena.
The objective of this thesis is to develop volumetric meshing methods for geological models. We propose a volumetric unstructured meshing method to build two mesh types: an adaptive tetrahedral mesh and an hex-dominant mesh (i.e. made of tetrahedra, triangular prisms, quadrilateral pyramids and hexahedra). This method generates first a tetrahedral mesh that can respect different types of data:
- a geological model defined by its boundaries to capture the structures in the volumetric mesh,
- well paths represented as a set of segments,
- a mesh size property to control the mesh element edge length
- a direction field to control vertex/element alignments inside the mesh to increase some features such as elements with right angles
Then, this tetrahedral mesh can be transformed in a mixed-element mesh. The method recognizes combinatorial relationships between tetrahedra to identify new elements such as prisms, pyramids and hexahedra. This method is then used to generate meshes whose features correspond to a given application in order to reduce errors during numerical computation. Several application domains are considered such as geomechanical, flow and wave propagation simulations.
The PhD committee members also included: David Ledez, Adrien Loseille, Géraldine Pichot, Jean-François Remacle, Jean Virieux.