SimScale CAE Forum

Transient flow analysis failure

Hello… as I continue some simple validations of Simscale and CFD I am having problems doing a simple transient flow analysis around a sphere.
With a very simple mesh I am unable to begin a transient analysis… after meshing it begins an analysis run but never proceeds past 0%… being able to stop or delete the process is impossible as it remains ‘greyed’ out. The only solution is to delete the project entirely and start over. Is it possible to do transient analysis with the publically available core hours? The estimate is for about 0.5 to 1 core hours before the run begins and I assume there is time available… my settings might be off (too extreme? although I thought it was simplified at a low time resolution – following other examples in the documentation – but it is difficult to check because the simulation control menus ‘grey out’)

Hi there!

Yes, transient analyses are also possible with the provided community quota. However, please make sure that your mesh is not too fine. You can reverse engineer some of the examples from the public projects library if you like, one example:

Also your mesh at the moment is quite coarse so you might refine that. Also I would give the solver some time too start as I am not sure what times you personally expect the solver to give you feedback.

Get your mesh correct at first and then the @cfd_squad and myself can jump back in again to help you out with the processing step. I assume you are interested in separation phenomena on a sphere/golf ball?



As always, thank you for your feedback. The sphere was just an extremely simplified model to understand the transient processing workflow… The mesh was extremely coarse as I was attempting to discover why the analysis would not commence (the solver wouldn’t initiate, even after hours). Some attempts would lead to an error, “not enough core hours” or similar, so the model was reduced to a bare minimum… I will continue to fiddle!

@dstokes if you are still facing the problem try changing the material from water to air. Since its a transient analysis, water might take more core hours.
hope this helps

Thank you for the response… I am having some success with a simple transient simulation, however, I am still having problems where >i suspect< simulation control parameters become out of range; resulting in a ‘greyed out’ response and the analysis freezing at 0% without showing an error (and then precipitating the need to delete the entire project to start again). It is difficult to narrow it down because of this. I will continue to experiment when I have the chance.