Skip to main content

New answers tagged

0 votes

Speed up finite element method solver with small features

To solve this problem, we put characteristic scale L=300 and then rescale all geometrical parameters on L, as result we have <...
Alex Trounev's user avatar
  • 46.3k
1 vote

Unwanted Oscillation in Solution Occurs When Solving Poisson-Nernst-Planck Equation

As one of the possibly solutions we can decrease accuracy and use explicit method as follows ...
Alex Trounev's user avatar
  • 46.3k
1 vote
Accepted

Singularity error when solving Poisson-Nernst-Planck equation

We can use FEM to solve this problem as follows ...
Alex Trounev's user avatar
  • 46.3k
3 votes

How to increase the mesh size in NDsolve

You can do that though a Method option but the exact option dependents on whether the DE is stationary or time dependent: ...
user21's user avatar
  • 40.1k
1 vote
Accepted

Finite element mesh not resolving small features

A slight increase of the accuracy goal helps: ...
user21's user avatar
  • 40.1k
3 votes
Accepted

Finite element method for 3D built-up structures using two materials

welcome back to FEM... The multi material section seems relevant for this. Here is how I'd do it. We start in exactly the same way you did: ...
user21's user avatar
  • 40.1k
2 votes

Boundary conditions issue with Laplace equation

In Version 14.0 this works: ...
user21's user avatar
  • 40.1k
4 votes
Accepted

Boundary conditions issue with Laplace equation

We can use OpenCascadeLink to generate mesh for this problem as follows (note, we rescale l, r, rs because the solution does not ...
Alex Trounev's user avatar
  • 46.3k
0 votes
Accepted

Numerically solved PDE of Ornstein–Uhlenbeck process on 2-Simplex violates conservation of probability

The initial condition was inconsistent and needed to exclude the boundary: ...
CRTmonitor's user avatar
1 vote

Boundary conditions issue with Laplace equation

It works if you remove one of the two balls. For example : : ...
andre314's user avatar
  • 18.7k
0 votes

Numerically solved PDE of Ornstein–Uhlenbeck process on 2-Simplex violates conservation of probability

Roughly your equation is $$\ \partial_t P =-\left(\frac{3}{2}\ - \ y \right) \ \partial_y \ P \ -\left(\frac{5}{2}-x \right) \partial_x \ P +\frac{1}{2}\Delta \ P \ + \frac{3}{2} \ P$$ by the fact ...
Roland F's user avatar
  • 3,967
1 vote
Accepted

SMTShowMesh with additional graphics in SMTRestart session

You did two errors. The "Show"->True option creates a new notebook cell, but it does not return the graphics. "Show"->False is correct in your case. See manual: 2)You have ...
JozeK's user avatar
  • 881
1 vote

Negative Jacobian for small finite element in AceFEM

The build in Jacobian check is for your case to restrictive. Received warning can be simply ignored in your case.
JozeK's user avatar
  • 881
1 vote

New interpolating function on the mesh from operations on other ones

EvaluateOnElementMesh does what you want to do.
user21's user avatar
  • 40.1k
2 votes

Solving a large number of coupled non-linear equations

For this equation it could be better to use implicit difference scheme in combination with FEM as follows ...
Alex Trounev's user avatar
  • 46.3k
3 votes
Accepted

Issue with a Piecewise Diffusion Problem

Change your bc to NeumannValue to force a FiniteElement-solution: ...
Ulrich Neumann's user avatar
8 votes
Accepted

Creating QuadElements from a set of points

ResourceFunction["FEMAddOnsInstall"][] ...
cvgmt's user avatar
  • 77.8k

Top 50 recent answers are included