[deal.II] Force and PK1

Dear all, I studied the step- 44 Tutorial Program and read already a lot about how to apply a Neumann contribution. But I have still two questions: In my case, I like to apply a force (not a force per unit reference area) as a Neumann contribution on the RHS. But for the Integral, Ni *

Re: [deal.II] Non smooth solution when the BC coincide with the processors boundaries?

On 02/15/2018 04:48 PM, Giorgos Kourakos wrote: I haven't forgotten the ConstraintMatrix::distribute. The code works with 1 processor I do set manually boundary ids but I reset them after every refinement. Isn't this enough to get the correct boundaries? I haven't cross out the other two

Re: [deal.II] Apply the inhomogeneous Dirichlet boundary conditions on the velocity in the mixed FEM

On 02/15/2018 09:24 AM, jie liu wrote: Setting 'a' equal or not equal to zero, it works when 'b' is equal to zero (homogeneous Dirichlet boundary condition on the gradient). Specifically, the convergence order of the solution is one order higher than the element degree of the solution, and

Re: [deal.II] Re: Problem compiling deal_ii with PETSc

Daipayan, 2018-02-15 11:17 GMT-05:00 Daipayan Sarkar : > Thanks for your help. I followed just as you mentioned in your reply and > now it works. For future, if I want to build any other external library > (e.g. Trillions) do I need to use cmake in the build directly to make

Re: [deal.II] Non smooth solution when the BC coincide with the processors boundaries?

Giorgos, there can be several reasons for this: 1. You forgot a ConstraintMatrix::distribute() call (after solving) 2. Your ConstraintMatrix is inconsistent (for example if you manually set boundary ids or values in the ConstraintMatrix) 3. If you do some kind of nonlinear iteration, you might

[deal.II] Apply the inhomogeneous Dirichlet boundary conditions on the velocity in the mixed FEM

Dear all, I want to solve an 1D Poisson equation with the inhomogeneous boundary condition on the gradient (velocity) using the mixed FEM. The equation reads I used step-20 to implement the mixed FEM. Since this step cannot deal with the inhomogeneous boundary condtion on the gradient, I

Re: [deal.II] Re: Problem compiling deal_ii with PETSc

Hi Bruno, Thanks for your help. I followed just as you mentioned in your reply and now it works. For future, if I want to build any other external library (e.g. Trillions) do I need to use cmake in the build directly to make a new executable linked to the Trillions external library? Best,

[deal.II] Wrong sign appears in VectorTools::point_gradient function when dealing with hyperball mesh

Dear all, I have some problems with the signs of VectorTools::point_gradient. Here's an example: I modified Step-4 of tutorial so that the mesh is a GridGenerator::hyperball with half of its boundary_id equal to one. After solving the problem, a function is called that prints

[deal.II] Non smooth solution when the BC coincide with the processors boundaries?

Hi deal.ii experts, I have the following issue and I'd like if you could give me directions what to look for. I'm attaching a figure from two consecutive iterations: The black line shows how the triangulation is split to different processors. The red line indicates a Dirichlet boundary