[EternalSeekerX]

Hello everyone,


I have been playing around with tutorials and validation cases. A tried a few pimpleFOAM cases and I learned about using the postprocess flag to calcuate vorticity and Q. I then learned about using paraview filters on how to visualize vortex shedding. I wonder if the same could be done using pisofoam motorbike case? Does pisofoam capture vortexs? And if so is there a Re limit to how useful it is to visualize the vortex?

[Tobermory]

Originally Posted by EternalSeekerX

Does pisofoam capture vortexs?

Yes ... the solver is capable of capturing vortex shedding, if it occurs, but of course you need to choose an appropriate mesh and suitable time step to resolve the shedding process. Just take a look at cylinder vortex shedding examples - there are plenty on the web. Bear in mind that this might be rather a challenge for a complex 3D shape like the motorbike tutorial ...

As a comment/question ... are you sure that the motorbike and rider do actually shed a coherent vortex street? If so, it would make riding a motorbike rather hazardous, don't you think?

[EternalSeekerX]

Originally Posted by Tobermory

Yes ... the solver is capable of capturing vortex shedding, if it occurs, but of course you need to choose an appropriate mesh and suitable time step to resolve the shedding process. Just take a look at cylinder vortex shedding examples - there are plenty on the web. Bear in mind that this might be rather a challenge for a complex 3D shape like the motorbike tutorial ...

As a comment/question ... are you sure that the motorbike and rider do actually shed a coherent vortex street? If so, it would make riding a motorbike rather hazardous, don't you think?

Thanks for the response. I have done a 3D square cylinder case and thought how neat the vortex shedding looks that I started looking for new cases. Found a few fase and car aerodynamics cases that have vortex shedding. I couldn't find any 3d airfoil cases so I thought about the les motorbike case. However I think I did miss a crucial thing. Doesnt any vortex shedding indicate an unsteady flow around the object? That would mean both the motorbike and rider would be unstable. So I see what you mean. Guess I got carried away 🤷*♂️

Thanks.

[Tobermory]

Haha - no need to apologise. It's always good to have an "enquiring mind" - whilst many of your ideas over your career may lead to a dead end, one could end being a gold mine! Keep on questioning, my friend, is my advice.