Hello,
I am a beginner in Nektar++ and have compiled some of my questions below. I would be glad if you can help.
1. Does IncNavierStokesSolver or any other solver support adaptive time marching? It seems to me that TimeStep, NumSteps, IO_CheckSteps, IO_InfoSteps, IO_CFLSteps are required by the solver. I was wondering if it would be possible to control
the time step with e.g. a CFL number constraint? Then all IO_* (most importantly CheckSteps) can be expressed in terms of simulation time (not time step).
2. Is it possible to calculate the gradient of only one specific variable? The gradient module calculates the gradients of all variables which produces unnecessary data, slowing down post-processing and increasing the size of the files. Is there
a better way than calculating the gradient and removing the unnecessary fields using removefield module?
3. Where can I find a use of the isocontours module of FieldConvert? I couldn't figure out what kind of output it gives, and what it expects as input.
4. Is it possible to map the results of a case to another where the meshes are neither at same refinement level nor at the same order?
5. Is there a way to control solver tolerance? The standard residual level allowed seems to be 1e-09, and how can I change it?
6. When visualising with ParaView (and also if you write a python script), the best way I know is to convert the chk files into vtu files. In each of those vtu files, the mesh is included, which increases its size. Is there a way to use one mesh
file (e.g. mesh.vtu or mesh.xml) and only convert the variables to some other format? This would reduce the storage space needed for a case. I would also appreciate it if you can suggest a totally new and a better way of visualising the results.
7. In the mesh.xml file created by NekMesh, the NUMMODES of the expansions are always 4, irrespective of the value of the ORDER parameter. Are those just placeholders, or should I change them after meshing? In the session file I set the NUMMODES
as 1
+ "the value of ORDER (in the mesh file)". Is this the correct way?
8. When using AeroForces filter, can you change the formatting of the output file? For example I want the time and the forces in scientific format with 10 digits precision, how can I make this happen?
Thank you in advance for your help!
Best regards,
Ilteber