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Search took 0.00 seconds. Search: Posts Made By: Tobermory
Forum: OpenFOAM Running, Solving & CFD January 11, 2023, 10:28
Replies: 28
Views: 2,656
Posted By Tobermory
It's not a myth - they really are more robust (at...

It's not a myth - they really are more robust (at least StarCCM+ is), and the article/blog that you linked (a really good read - thanks!) explains why - commercial reality in essence.

It's still...
Forum: OpenFOAM Running, Solving & CFD July 4, 2022, 10:22
Replies: 28
Views: 2,656
Posted By Tobermory
That must be really frustrating. I don't have...

That must be really frustrating. I don't have any recent experience with Ansys Fluent or CFX ... my recollection is that StarCCM+ was more stable, but I do not have access to that at the moment.
Forum: OpenFOAM Running, Solving & CFD June 23, 2022, 03:51
Replies: 28
Views: 2,656
Posted By Tobermory
Yes - that's right. I am specifying the (total)...

Yes - that's right. I am specifying the (total) pressure on the upstream boundary, so I have a zeroGradient BC on U ... you can't specify both p & U since that overconstrains the problem. On the...
Forum: OpenFOAM Running, Solving & CFD June 21, 2022, 06:59
Replies: 28
Views: 2,656
Posted By Tobermory
No problem! My upStream patch is on the...

No problem!

My upStream patch is on the upstream end of the "nozzle" - ie the far left vertical boundary in the plots. The downStream patch is to the right of the edge of the picture (only part...
Forum: OpenFOAM Running, Solving & CFD June 21, 2022, 04:46
Replies: 28
Views: 2,656
Posted By Tobermory
Thank you for giving me a giggle so early on in...

Thank you for giving me a giggle so early on in the morning. I love the idea that you think that two to three cells are enough to resolve fully the complex flow features, including free shear layers...
Forum: OpenFOAM Running, Solving & CFD June 21, 2022, 04:40
Replies: 28
Views: 2,656
Posted By Tobermory
Did you apply the full pressure from the start? ...

Did you apply the full pressure from the start? I needed to ramp up my pressure over several thousand iterations, to give the pressure solver a chance. I used a uniformTotalPressure condition:

...
Forum: OpenFOAM Running, Solving & CFD June 20, 2022, 17:06
Replies: 28
Views: 2,656
Posted By Tobermory
Oliver - it is possible to use rhoSimpleFoam for...

Oliver - it is possible to use rhoSimpleFoam for transonic/sonic cases - see the attached results from a nozzle flow at a pressure ratio of 6.8, run with rhoSimpleFoam. I always prefer to use a...
Forum: OpenFOAM Running, Solving & CFD June 20, 2022, 04:59
Replies: 28
Views: 2,656
Posted By Tobermory
This is the bit that puzzles me - why would...

This is the bit that puzzles me - why would anyone run a CFD simulation with just two cells across the domain? That fails the basics of Best Practice. I am not really interested in what that...
Forum: OpenFOAM Running, Solving & CFD June 20, 2022, 04:30
Replies: 28
Views: 2,656
Posted By Tobermory
Dear Arjun - thanks for your input, and make no...

Dear Arjun - thanks for your input, and make no mistake - I am a BIG fan of starccm+ ... and have used starccm+ and StarCD before that since the early 90s. My earlier comments about stability were...
Forum: OpenFOAM Running, Solving & CFD June 18, 2022, 07:00
Replies: 28
Views: 2,656
Posted By Tobermory
Domenico - the numerical cleanliness of OF...

Domenico - the numerical cleanliness of OF depends on the schemes (divScheme, etc.) that you choose, of course, but in OF you can at least choose to run with very little artificial stability by using...
Forum: OpenFOAM Running, Solving & CFD June 17, 2022, 13:26
Replies: 28
Views: 2,656
Posted By Tobermory
One of the difficulties I have observed is that...

One of the difficulties I have observed is that the OpenFOAM solver schemes are very "clean" compared to commercial codes like StarCCM+ of Fluent, and this means that if you have a fine mesh, then...
Showing results 1 to 11 of 11

 
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