# Questions tagged [mesh]

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201 views

### Once and for all: Which FEM plattform should I use for a very large multiphysics simulation?

I'm fooling around with the decision on how to build a multiphysics simulation for too long now (also several questions in this forum). First, I thought it would be possible/necessary to write most of ...
107 views

### FEM with elastic inhomogeneous properties leads to mesh-induced anisotropy

I'm solving an elastic homogenization problem and I'm having problems with mesh artifacts. I would like to first give a brief summary of what I do: I have a system with inhomogeneous (but isotropic) ...
96 views

### Is it possible to retain sets (physical tags) after remeshing the model in Gmsh?

I am currently working on a remeshing algorithm for Abaqus using Gmsh as part of my Bachelors thesis and I seem to be stuck at some point. I am able to remesh .geo and .msh files using the script ...
114 views

### Creating FEM mesh for image region — what is the most suitable shape function?

I wish to create a FEM mesh to solve an inverse elasticity problem, for an irregular domain. This domain is given by a medical image, so it is discretised and each square on the grid has one scalar ...
80 views

### Literature on numerical solving based on multiple meshes?

Consider solving a differential equation system for 1D, 2D, or 3D. It involves various input and output "field" variables, which, more often than not, correspond to various physical quantities ...
69 views

### Data format for Cartesian mesh with cut cells

Is there a mesh data format which is particularly well suited for Cartesian meshes with Dey-Mittra style cut-cells? Ideally, one which does not require converting the cut-cells into a more general ...
143 views

### Produce one smooth curve on one triangle mesh

I hope to get one smooth curve on one triangle mesh. I get one path on the mesh at first. The path consists of vertices of the mesh. I can see the path from the image below. Each one green dot ...
21 views

### Finding isocontour lines, populating points on said lines (in MATLAB)

I'm trying to extract data from a potential field. I have an example code of a potential field, using meshgrid in MATLAB. I've pasted the code below. What I'd like to do next is 'convert' this field ...
68 views

### Compute mass matrix in vibrations problem by using finite element method

I have to compute the mass matrix of a Hexahedral mesh. There are 3 methods to compute mass matrix. I'm interested in one method which consists of dividing the mass of the element by the number of ...
146 views

### How to choose seed in flood/fill algorithm

I was able to draw to the outer airtight boundary of hole. Now I would like to implement interior flood/fill algorithm. To get an internal seed, only one method comes to my mind which is testing ...
36 views

### 2D Test cases for overset meshes

I developed a parallel 2D overset mesh (chimera) assembler and I would like to test a large scale problem. I don't want to make up a test case myself but rather want something standard. Would you ...
84 views

### Mesh partitioner with user-defined overlap

I am looking for a mesh partitioner, where I can specify overlap, for example h = 3. I have looked into metis, but I wasn't able to find such a functionality. Is there any other package which ...
111 views

### Conservation at grid interface in adaptive mesh refinement

I am using adaptive mesh refinement to solve one dimensional inviscid Burgers equation. However I am facing some difficulty to handle grid interfaces which are not uniform (coarse-fine grid interface)....
524 views

### Equilateral triangle based mesh generation by intersection

In work I am currently working on I need to mesh some structure with equilateral triangles to study it using a kind of discrete element method known as spring networks or Lattice model. To mesh the ...
101 views

### Algorithm for merging mesh with cad file

I am writing the pre processing program for a porosity based cfd project we just started. Basically I have a 3 dimensional mesh made of cubes and I need to import a STL file over it, and calculate how ...
19 views

### Show deformed mesh in Comsol

I am using COMSOL Multiphysics 5.2a in order to do thermal, mechanical and thermo-mechanical simulations. Due to a boundary load, my components get deformed which I can simulate very well. However, ...
60 views

### FEM Meshing artifact at nodes with fewer neighbors

I wrote a 2D-FEM solver to solve some diffusion process and wanted to verify my code with a test problem. The input was $f(x,y) = x^2+y^2$ and I applied the stiffness matrix on it to get $\Delta f = 4$...
17 views

### Volumetric Mesh Cutting Algorithms For Simulating Sculpture

I am interested in whether there an available algorithms to give me insights on how to cut a volumetric mesh?
35 views

### Adding a boundary surface on a STL model in Gmsh

Background info I want to run brain simulations with models from the PHM repository (not relevant to the problem but suits the narrative) which are shipped in STL format. The meshes of the STL have ...
22 views

### RANS equations in the ALE formulation

I am simulating an incompressible flow of a newtonian fluid over an oscillating plate using OpenFOAM . As far As I know, in this case, OpenFOAM uses the Arbitrary Lagrangian Eulerian formulation. ...
33 views

### Import stl file into Gmsh and create a 3d mesh for CFD

I am trying to develop a case study for teaching CFD. To this end, I am using OpenVSP, Gmsh and SU2. I have created a wing in OpenVSP, exported the CFD mesh as .stl file. Opened the .stl file in Gmsh ...
27 views

### When semicoarsening is needed in multigrid method?

I am trying to understand multigrid in deep and all the coarsening techiques. So,assuming a 2D grid when semicoarsening is prefered instead of standard coarsening?What is the error's behaviour when a ...
77 views

### FEniCS, refinement not 'respecting' domain boundary

Short question: how to ensure that extra points are not included as 'boundary' points after calling the refine function. More details. I am working with a hexahedral mesh in $3$d. Let $X$ be the set ...
22 views

### Direct and Inverse efficient mapping of 3D cartesian positions in a 1D array

I saved a sample of $N$ Cartesian locations $\{x_i, y_j, z_k\}$ inside a one-dimensional array $\mathbf{a} = \{a_l\}_{l = 1}^N$. How can I access back (efficiently) the $l$-location of the array \$\...
47 views

### Determining the indices of a VTK mesh

I am trying to assign fixed constraint at specific indices of VTK mesh, however, I only can view STL file in a blender as follows: Upon assigning the favored indices in my scene at the SOFA physics ...
79 views

### How to read data from simply formatted text file (c++)?

Mesh information like points, faces and cells is to be stored into separate files: e.g. for points file: # points data: x y z N_Points 100 x1 y1 z1 x2 y2 z2 ... cell file: # cells data: ...
51 views

### Stokes Equation fails to converge for an ellipse

This might be because of the mesh, but the following code blows up for all values of b not 1. Does anybody have any experience working with the ellipse mesh in Fenics? ...