Re: [deal.II] Questions on Step-18

HI Michael. > To be honest, I have a hard time to understand the three-filed formulation in > Step 44. That’s a fair comment, and a known deficit in our current tutorial list. I hope that by the end of the year we will have a tutorial that uses one-field elasticity, and would be a much

RE: [deal.II] Questions on Step-18

Andrew, thanks for confirming that. The missing 1/2 does not affect the demonstration of functionalities of deal.II but it may change the results. Jean-Paul, thanks for commenting on my second question. I want to study the pure geometrical nonlinear elasticity (large deformation with linear

RE: [deal.II] Different get_function_gradients

Hi Jean-Paul,Thank you so much for your explanation. That totally makes sense. These different functions exist for implementing  different weak forms easily. Though I can get everything using (1), but I would prefer using the others when I try to extract components of the gradient.  Best,Michael 

Re: [deal.II] Deal.II compilation error issued at example steps phase

Dear Saad, Well, after briefly browsing the Ginkgo repository online, its a bit of a mystery to me. The mask looks to be declared by this call to this piece of

Re: [deal.II] Questions on Step-18

Hi both, Jean-Paul has addressed the second point nicely. On the first point, I think there is a 1/2 missing. The curl of the velocity gradient is the vorticity which is twice the angular velocity - hence I think you need a 1/2. Happy to be corrected on this. Best, Andrew > On 24 Jun 2021,

Re: [deal.II] Marking Boundary Nodes in Triangulation

Hi Chen, Is the DoFTools::extract_boundary_dofs() function perhaps what you’re looking for? Best, Jean-Paul > On 23. Jun 2021, at 10:08, Chen R wrote: > > Hi all, > > So I am trying to

Re: [deal.II] Different get_function_gradients

Hi Michael, > Does the (1) do all the work that the last two do? I.e., (1) gives the whole > chunk of gradient, and the last two extract the scalar and vector parts from > the chunk, respectively. > They are very closely related. (1) has no knowledge on the nature of the field(s) for which the

Re: [deal.II] Questions on Step-18

Hi Michael, I cannot comment on the first question, but might be able to assist a bit with the second. But may I first ask, what precisely are you trying to achieve with this extension? As interesting as it is, in the past I had found step-18 to deviate too significantly from the “classical”

[deal.II] Different get_function_gradients

After reading the documentation on Handling vector valued problems (The deal.II Library: Handling vector valued problems (dealii.org) ), I have the following question. What are the differences between the three

[deal.II] Integrating with curved manifolds

I am working with a mesh generated from subdivided_cylinder, and am wondering whether the area and volume should be assumed to match that of a true cylinder, or if it only converges to that when many refinements are made. I would like to calculate the total energy of the system by integrating

Re: [deal.II] adaptive mesh refinement for Navier Stokes

Hi Andrew Jack, This is a reasonable start but, as the error messages state, you need to implement some more features in your code for this to work. In particular, step-26 has a separate function that reinitializes all of the DoFs, sparsity patterns, and matrices called setup_system() - there

Re: [deal.II] Higher order elements

Hi Hermes, We typically use lower-order elements in the tutorials, but FE_Q supports arbitrarily high degrees - for example, step-48 uses degree 4 elements, and the hp tutorial programs will use up to degree 7 or 8. We don't have plots for these shape functions but they are implemented. Best,

[deal.II] Higher order elements

Dear all, I would like to ask how to handle higher-order elements. I would need to use 4th order. Looking at the first tutorials, I found that using FE_Q, it is possible to use only 1st and 2nd order.

[deal.II] Re: adaptive mesh refinement for Navier Stokes

Hello, The error message is pretty clear: you are calling the function setup_system() but you didn't define it. I am guessing the function exists in Step 26 but not in Step 35. Best, Bruno On Thursday, June 24, 2021 at 2:40:56 AM UTC-4 jack urombo wrote: > I am working on a adaptive finite

[deal.II] adaptive mesh refinement for Navier Stokes

I am working on a adaptive finite elements for flows. For starters I want to base my simulation on Step 35 and introduce the refine_mesh( )  like in Step 26 to it: See attached code snippet. When I make I get the error message: /[ 50%] Building CXX object