SIGMA

Scalable Interfaces for Geometry and Mesh based Applications

Urban Modeling

Posted by in Meshes, Meshkit, News, RGG, SIGMA

Generating conformal hexahedral meshes with boundary layers for urban buildings and atmosphere is a challenging task. We have created a tool that reads a .geojson file with 3D building models and creates a CAD model and mesh for the buildings and the urban atmosphere for CFD simulations. We are looking at different strategies to automate the entire CFD model creation process.  The same geometry...

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Building Lasso

Posted by in Lasso

Lasso is now a part of MOAB, use –enable-irel when configuring MOAB. Prerequisites: Lasso requires iMesh and iGeom implementations, so you’ll need to build/install those first. See BuildingMoab and BuildingCGM for instructions on the ANL implementations of those. Because of the way Lasso restores relations between geometry/mesh entities, it may only work with those implementations...

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Full Core model of Korean MONJU reactor

Posted by in RGG

Assygen is capable of creating assemblies with varying properties in axial and radial direction. Coregen is designed to operate in parallel allowing the core creation, merging of nodes and saving the mesh file in parallel. This mesh, which uses 101 million volume elements to describe the reactor core, was generated by SHARP simulation tools in as little as seven...

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HGTR Fuel Brick

Posted by in RGG

Coupled Thermal-Irradiation-Structural Analysis of HGTR Fuel Brick Using ABAQUS Assygen and CUBIT were used in generating the models for this structural analysis. Axial and radial mesh size APREPRO variables in the template journal file created by Assygen were modified to create the desired mesh quality. The material considered is H-451 transversely isotropic graphite. At the end of 4.6 years...

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CoreGen Input File Keyword Definitions

Posted by in RGG

1. Geometry: Surface or volume core models can be generated; if unspecified, the default is to generate a volume model.   2. GeometryType: The GeometryType is specified as rectangular, hexflat, or hexvertex (see section 2 of this paper  for a description of the hexagonal lattice types).   3. GeomEngine: This keyword typically takes the ‘OCC’. Note, specified engine type...

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AssyGen Input File Keyword Definitions

Posted by in RGG

NOTE: common.inp is a reserved file name for RGG process, when present AssyGen loads it for all assemblies that form the core. This avoids repetition of keywords across all assemblies forming the core model. 1. Geometry: Assembly geometry can be output as a collection of 2D surfaces, or as a collection of volumes swept out by those surfaces. If this keyword is not used, AssyGen produces a...

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NUSCALE mesh model

Posted by in Meshes

Initial geometry Fluid geometry is described by subtracting from an embedding cylinder some core details. Model will be used for CESAR project. Webcutting There are 2 planes of symmetry ( xz and yz planes). The difficult geometry, hard to sweep in z direction, is around some spacers at z ~=311 mm    geometry is processed in Cubit 12.2. After webcutting, the geometry has 781 volumes, most are...

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Simple hexagonal assembly (sahex)

Posted by in Meshes, RGG

This is a small hexagonal nuclear reactor core assembly used for small-scale testing of mesh generation and multiphysics analysis of reactor cores. The geometry is generated using the Reactor Geometry (& mesh) Generator, RGG, and meshed using Cubit. RGG input: sahex.inp CUBIT .jou file generated by Assygen: sahex.jou Geometry: ACIS, STEP Meshes: 512K hex (ExodusII, h5m), 4M hex (ExodusII,...

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OECD/NEA-Vattenfall T-Junction Benchmark

Posted by in Meshes, Meshkit

The T-Junction mesh was generated for the OECD Vettenfahl T-Junction benchmark; this exercise was a blind benchmark of various CFD codes.  The Argonne code Nek5000 participated in this benchmark, using the mesh shown below.  The mesh was generated with Cubit 10.2, then modified to extend the (top) inflow and (side) outflow pipes. Mesh Cutaway view of volume mesh Shape quality metric for this...

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64 Bricks

Posted by in Meshes

This is a simple geometry consisting of 64 geometric bricks arranged in a 4x4x4 lattice (in the figure above each geometric volume is a different color). 64 different material sets are allocated, along with 3 Dirichlet sets and 3 Neumann sets. Meshes consisting of hexes and tets have been generated for this model. ‘cub’ refers to meshes stored in CUBIT .cub format, ‘h5m’...

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