#fenics

Mastodon #introduction: TuxRiders is a journey to research experiences using free and #opensource scientific computing programs, which aimed to demonstrate their power for real-world scientific research.

In our #YouTube channel, we regularly talk about #FiniteElement, #EngineeringMath, #PDEs, #NumericalMethods, #FreeFEM, #FEniCS, #ParaView, #C++, #Python, #OpenFOAM, and #Linux.

Hello there! #introduction

I am a postdoc at Université Laval in Québec working in collaboration with Michelin. My current work is about #ErrorEstimation for #FiniteElements methods. More precisely, I am working on gradient reconstruction for multimaterial problems.

I am also a #fenics user and I am interested in #NonLocalModels and more precisely in the error estimation in the finite element discretization of fractional partial differential equations.
#WelcometoMastodon
#WelcometoMathstodon

RT @SDISsavoie: [FENICS]
Engagés en Gironde dans le cadre du #MPCU, le @SDISsavoie, le @SDIS_74, le @SDMIS69 et les @Pompiers_13 ont déployé la solution de #communication #FENICS
Avec cette solution, la @SecCivileFrance a pu prendre en compte les différents renforts européens
#résilience

: https://nitter.eu/laurencefarreng/status/1566012397592133632

Finally made my 2D magnet post. In this example I do a simple demonstration of finding a magnetic field from a coax, and verify the result with an analytical solution. I then use the same method to find the field inside a dipole magnet of the type used at the LHC; a cos(phi) magnet. https://comphysblog.wordpress.com/2020/08/19/2d-magnetostatics-cos%cf%86-dipole-magnet/

#fenics #physics #finite_element_analysis

Just made a short post about how to simulate electrostatic nonuniform charge density distributions with FEniCS; that is spatially varying charge density distributions. This could be useful for simulating things like particle beams which are commonly assumed to have Gaussian (or similar) distributions. This is a small extension of a previous post about how to simulate uniform charge density distributions.

https://wordpress.com/post/comphysblog.wordpress.com/988

#fenics #physics #opensource #python #ham

My latest post is about using boundary conditions to assume symmetry in a finite element electrostatics problem.

To demonstrate Neumann boundaries I solve the Laplace equation for a coaxial geometry using 1/4 of the cross section. I then find the fields of a differential pair transmission line using half the cross section and a Dirichlet boundary.

This is all done with FEniCS, the open source finite element solver. #physics #python #opensource #ham #radio​ #fenics

https://comphysblog.wordpress.com/2019/07/15/assuming-symmetry-with-boundary-conditions/​​

Finally finished my post on electrostatics with linear dielectrics using the open source finite element solver FEniCS. It's surprisingly easy!

#physics, #rf, #opensource, #python, #fenics

https://comphysblog.wordpress.com/2019/01/12/electrostatics-with-linear-dielectric-materials-using-fenics/

After a couple of months without a new post I've started writing about simulating charge distributions, rather than just boundary value problems. I'll explain how #FEniCS can calculate the electrostatic fields of arbitrarily shaped charge densities, which are specified with mesh subdomains. These will have hard edges for now but I want to look into having more general charge distributions.

I've also run 3D simulations for calculating capacitances between arbitrarily shaped conductors and 2D linear dielectrics. I need to do some more testing & comparison with other FEA tools/ analytical methods before I publish any posts. Seems to be going well though!

Spent some time this week implementing my own solver for Laplace's equation in GNU Octave, for FEM:ing electrostatics, and for my own sanity. Attached pic shows computed voltages for a setup in the lab. I even managed to speed the solver up considerably using BiCGSTAB :]

Then today a friend of mine tipped me about #FEniCS, a libre set of FEM tools. Is anyone on here familiar with it? It seems suitable for my needs, and having something mature other than COMSOL would be nice

Small update to the TEM mode analysis with #FEniCS example.

I've added in a calculation for the mutual capacitance and self-inductance per unit length of the transmission line.

https://comphysblog.wordpress.com/2018/09/06/tem-mode-analysis-with-fenics/

#opensource #physics #python #ham

I've just finished my new post: TEM mode analysis with #FEniCS an #opensource finite element differential equation solver. https://comphysblog.wordpress.com/2018/09/06/tem-mode-analysis-with-fenics/

In this post I calculate the electric and magnetic fields on a coaxial cable, characteristic impedance of the line, the Poynting vector, the conductor and dielectric loss, an estimated loss coefficient, Q-factor and s-parameter for a given length of cable.

Coax has been a useful example for comparisons with analytical results but the methods are very general. TEM modes of systems with different geometries can also be analysed with the exact same techniques!

Very happy to hear any comments, corrections or suggestions.

#physics #ham #python

Starting my next post which will be about the TEM mode on a two-conductor transmission line. Specifically I'll be looking at a coaxial geometry and using #FEniCS to calculate the field distributions, the characteristic impedance and the Poynting vector. Just had a go and it all seems to be working.

While I'll focus on a coaxial geometry the method can be extended to more complicated geometries just by changing the mesh & boundaries. I've just had a go at an odd mode impedance and it came out just right!

The best thing about this post will be how easy it is.

#physics #electromagnetism #HAM #radio #Maxwell #opensource #python

3D electrostatics example using #FEniCS. In this example I solve the Laplace equation for two concentric spheres to obtain an electric potential and take the gradient to find the electric field. The results are then compared with an analytical solution.

The geometry is produced in FreeCAD and the mesh/ boundaries produced with Gmsh.

https://comphysblog.wordpress.com/2018/08/26/3d-electrostatics-using-fenics/

Please let me know if you have comments or corrections!

#physics #electromagnetism #opensource #python