Elmer Discussion Forum

Hi everyone, I am trying to simulate an electromagnetic particle trap. Is it possible to get particles "stuck" on specific boundaries on purpose? So my goal is to track particles through an electrostatic field and reduce the velocity of particles to zero that hit certain boundaries. I expe...

Hello, I am currently trying to simulate the movement of charged particles in an electromagnetic field. The field consists of an electrostatic field generated by a set of electrodes and a constant magnetic field acting in one direction (earths magnetic field). The interaction of the particles with t...

Hi peter,

thank you very much for fixing the problem!

carsten

How many steady state iterations do you perform? If only one, you should increase that number. Otherwise, if you start with the potential zero your source term is also zero in the first iteration.

carsten

Hi Sounil, Delta(f) = f is usally not the Poisson Equation. The Poisson Equation is Delta(f) = SomeFunc. If you now have a solution f0 than Delta(f0) = Delta (f0 + Constant) = SomeFunc. If your source term depends on your solution and you use a poisson formulation which assumes a source term which d...

Hi Sounil, firstly, I think this is the wrong section of the form. The Elmer Solver section would be more appropriate. Your problem is simple: You need at least one dirichlet boundary condition for a unique solution. If you have only neuman boundary conditions in your domain you have an infinite num...

Hi Peter,

did you have any time to take a look on the NaN example?

carsten

Hi, The basic FEM approach is: 1. Discretise the domain of interest with a number of simple geometric elements (tetraeder, bricks, prisms) 2. Approximate the field quantities (pressure, temperature, velocity ...) with a set of basis functions with compact support 3. Find some form of weak formulatio...

Hi Peter,

her is the small test case for the "NaN in the first step" problem. Simply extract an run with ElmerSolver.

carsten

Hi Peter,

I prepare a small example and upload it as soon as possible.

carsten