72 results about "Volume mesh" patented technology

A multi-scale finite-volume (MSFV) method to solve elliptic problems with a plurality of spatial scales arising from single or multi-phase flows in porous media is provided. Two sets of locally computed basis functions are employed. A first set of basis functions captures the small-scale heterogeneity of the underlying permeability field, and it is computed to construct the effective coarse-scale transmissibilities. A second set of basis functions is required to construct a conservative fine-scale velocity field. The method efficiently captures the effects of small scales on a coarse grid, is conservative, and treats tensor permeabilities correctly. The underlying idea is to construct transmissibilities that capture the local properties of a differential operator. This leads to a multi-point discretization scheme for a finite-volume solution algorithm. Transmissibilities for the MSFV method are preferably constructed only once as a preprocessing step and can be computed locally. Therefore, this step is well suited for massively parallel computers. Furthermore, a conservative fine-scale velocity field can be constructed from a coarse-scale pressure solution which also satisfies the proper mass balance on the fine scale. A transport problem is ideally solved iteratively in two stages. In the first stage, a fine scale velocity field is obtained from solving a pressure equation. In the second stage, the transport problem is solved on the fine cells using the fine-scale velocity field. A solution may be computed on the coarse cells at an incremental time and properties, such as a mobility coefficient, may be generated for the fine cells at the incremental time. If a predetermined condition is not met for all fine cells inside a dual coarse control volume, then the dual and fine scale basis functions in that dual coarse control volume are reconstructed.

Methods for indoor 3D surface reconstruction and 2D floor plan recovery by segmenting a number of objects and building structure elements from a building scan using an electronic computing device are presented, the methods including: causing the electronic computing device to capture the building scan, where the building scan includes a number of scan points; pre-processing scan data from the building scan; generating an octree and a 2.5D model from the pre-processed scan data; extracting interior and exterior volumes from the octree model and the 2.5D model; and meshing the extracted volumes to generate a 3D object geometry and a 3D building geometry, where the 3D object geometry corresponds with the number of objects and the 3D building geometry corresponds with the indoor 3D surface reconstruction of building structure elements.

The method enables a non-homogeneous diffusing object to be examined by illuminating the object with a continuous light by means of a light source. It previously comprises reconstruction of the three-dimensional spatial mapping of an attenuation variable representative of the diffusion and absorption non-homogeneities of the object, by resolving a diffusion equation∇2F({right arrow over (r)}S, {right arrow over (r)})−k′2({right arrow over (r)})F({right arrow over (r)}S, {right arrow over (r)})=ASδ({right arrow over (r)}−{right arrow over (r)}S).In the diffusion equation, AS is a constant, {right arrow over (r)} the spatial coordinate of any point of the mesh of a volume at least partially containing the object, and {right arrow over (r)}S the spatial coordinate of the light source. The transfer functions of an equation used for reconstructing the distribution of fluorophores integrate the attenuation variable reconstituted in this way.

A method for rendering an object includes determining illumination values for surface points on the object, associating a grid including vertices and voxels with the object, determining illumination values associated with vertices from illumination values for surface points on the object, performing one or more low pass filters on the illumination values associated with the vertices to form compensation values associated with the vertices, and determining compensated illumination values for the surface points by combining the illumination values for the surface points and the compensation values associated with the vertices.

A method for editing a volume-based model imaging geological structures. An initial volume-based model comprising a volumetric mesh and updated geological data defined within a region of the model is received. The volume-based model is decomposed by converting the volumetric mesh into surface meshes linked by stratigraphic fibers to generate a surface-based model. The defined region of the surface-based model is edited by editing positions of control nodes of the surface meshes along the stratigraphic fibers in the defined region of the model so as to fit the updated geological data. The plurality of stratigraphic fibers are updated based on the edited positions of the control nodes so as to fit the updated geological data. The edited surface-based model is meshed to generate an updated volume-based model comprising a volumetric mesh defined by the edited positions of the control nodes. The updated volume-based model is stored and / or displayed.

In a method for domain decomposition for generating unstructured grids, a surface mesh is generated for a spatial domain. A location of a partition plane dividing the domain into two sections is determined. Triangular faces on the surface mesh that intersect the partition plane are identified. A partition grid of tetrahedral cells, dividing the domain into two sub-domains, is generated using a marching process in which a front comprises only faces of new cells which intersect the partition plane. The partition grid is generated until no active faces remain on the front. Triangular faces on each side of the partition plane are collected into two separate subsets. Each subset of triangular faces is renumbered locally and a local / global mapping is created for each sub-domain. A volume grid is generated for each sub-domain. The partition grid and volume grids are then merged using the local-global mapping.

Method for generating a 3D grid, and for defining a material property model on the grid, to use, for example, in a reservoir simulator. A mapping is defined (61,71) to a design space in which the material property is described as a piecewise smooth implicit or explicit function in three dimensions. Grid geometry is constructed only in the physical space of the model (62-65,73-76), and no grid is required in the design space. The material property, for example permeability, is sampled in the design space (66,77) to populate the cells in the grid constructed in the physical domain. Prismatic grid cells may be truncated based on faults and horizons (65), or maybe conformed to fault surfaces using a 3D parameterization of the model (76). Only forward mapping, i.e. from the physical domain to the design space, is required.

A method of computer simulation of an aerodynamic behavior of an aircraft in flight close to the ground includes generating a volume mesh of a three-dimensional geometric domain. The volume mesh is at least partly delimited by a three-dimensional geometric model of the aircraft and by a plane modelling the ground. The volume mesh defines a computational domain. The method also includes imposing a uniform boundary condition on the plane comprising a predetermined speed vector with a non-zero tangential component and a non-zero normal component, and solving a discrete numerical model of the Navier-Stokes equations by computer on the volume mesh with the uniform boundary condition imposed on the plane to obtain a numerical solution of a fluid flow inside said computational domain.