SimScale CAE Forum

Workshop 2 Session - 1 Homework: Optimization of a wing - Part II


Hi have been trying to run the Straight Wing model but I keep getting the following error.

I have tried re-meshing, and I have checked all my boundary conditions and they seem to agree with the tutorial. Does anyone have any ideas?



As I am trying to run the second simulation, for the winglet and a got the following error:

‘‘The job execution was aborted, possibly due to a numerical instability. Review the log to identify reasons: unphysically large field values, extremely small time step size, etc. Modifying numerical settings and time step size could resolve the issue.’’

Any ideas/suggestions


Hi @sjesu_rajendra, Is this supposed to turned in at the same time as part 1?


Hello Sam,

I cannot select the Domain “Aircraft blended winglet mesh”, do you know why?

Also, I cannot run the simulation due to: “The maximum run time of this job would exceed your computation quota.
You can try to adjust the settings under ‘Simulation Control’ and to create a new run.”

I have modified the time value without success.
Thank you for your help.

Best regards,



Hi @arusu and @mchristiansen ,

I see that you are using the Premium Test Account which has only 200 free core hours (CH) usage, but has the possibility to maintain private projects. I can downgrade your account to free community account, in which case you get 3000 CH for carrying out the simulations. Please let me know if I can proceed with the same.

@mchristiansen The reason for not being able to select your “Aircraft blended winglet mesh” - could you please check if the mesh was successfully generated? If so it should be possible to select it to setup the simulation. In case you still have issues please send me a public link/project invite so that we could look into it.



Hey @cjquijano ,

I believe the issue is with the Inlet-Outlet boundary condition. The turbulence settings are not mentioned (kept as 2D empty) and hence the solver doesn’t know how to take up the turbulence properties. Please change these settings and try to re-run the case.



Hi @Andreas_Lianos ,

The mesh seems to be inconsistent - it is always important to maintain the aspect ratio of cells. In the current case the number of cells in Y-direction can be increased to avoid this problem. The simulation run should be stable when this is corrected.



Hi @oscarcorripio,

The submission form is for part 1 and 2 together. Please submit the homework with completed mesh, simulation and post-processing.



Hello Sam,

Please downgrade my account to free community account.
I will reprocess the mesh, this is the link of my project.

Thank you.




I keep having problems with the second simulation, for the wing with winglet. It keeps giving me the error that it cannot retrieve some information. Any ideas?

Thanks in advance,
Andi Mararu


Hello Sam,

I generated the second mesh again, it says is OK but I can’t select it in the Simulation Designer…



Sam, now the mesh selection is working, only I have the time simulation limitation issue due to my account plan.

Thank you for your help.



Hello Matias (@mchristiansen),

I have changed your account to free community plan. You can now continue with your simulation.

I imported your project, and it turns out I can select the new mesh (blended winglet) to set up the simulation. Could you please check again and let me know if there are issues!



Hey Andi (@AndiM),

I see that your simulation run is under progress, I believe you have overwritten the old error. Please let me know if you still have issues when it is over!



Thank you Sam. Indeed I have overwritten them. At first they stated they are out of memory and then that they cannot retrieve the data that needs to be simulated. I will get back to you as soon as it finishes.

Thank you,
Andi Mararu


Hi Sam,

Just to verify, I submitted the HW with only the first part. Now I have finished the second part in the same project, do I need to resubmit or will i be automatically updated so long as it is finished before the due date?



Hi @oscarcorripio,

When you generate a project link the status of the project at that moment is stored, and importing from the link results in retaining the information and changes before the link was saved. Hence you have to do another submission. Your first project link might have information only until meshing, they are not updated as you do changes to the project.



Hello, I have a problem with the first wing configuration, with the wing with winglet simulation went fine and I have good results, but with the first configuration even that the simulation ended succesfully, the results are not right. I have bigger pressure on the upper surface, and the flow is all turbulent.
I duplicated the winglet simulation and applied to normal wing and I get the same results.
Is there something obvious that I am doing wrong?

Thank you,


Good evening!

I am having troubles to show any post-processing results in the display window. It seems from the residuals and the force monitor that both of my simulations have converged nicely. I’ve tried to re-open the simulation multiple times in different browsers without any success. Do you know other things I could try to finish this project in time?




Hi Thomas,

Unfortunately I’ve noticed that it is better to place inquiries in the morning (eastern time) given that right now its 10pm in a big chunk of Europe where I believe most of the staff is located. I looked at your project:

and it seems like the convergence is correct. For me too it took a while to do the post processing, mostly I left it loading and doing the steps slowly. Make sure that when you click in the post processing window you the click on the solution field. Maybe verify that the rendering is not being done locally and avoid making changes you do not need (stick the instructions without rotating the geometry or zooming around… that might help a little bit with the rendering operations). Are you getting error messages or is the loading just taking a while?