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Search took 0.00 seconds. Search: Posts Made By: vkrastev
Forum: OpenFOAM November 16, 2010, 10:26
Replies: 67
Views: 49,035
Posted By vkrastev
I've removed the limiter on grad(p), but as you...

I've removed the limiter on grad(p), but as you can see from the results posted below now the solution doesn't even seem to converge (the Run18 settings are the same as Run15 but with only...
Forum: OpenFOAM November 10, 2010, 09:28
Replies: 67
Views: 49,035
Posted By vkrastev
Ok, after several runs, in which I have tried to...

Ok, after several runs, in which I have tried to set only the divScheme for U to te linearUpwindV option (the divSchemes for k and epsilon are left to be upwind), that is what I have obtained:
...
Forum: OpenFOAM November 9, 2010, 04:44
Replies: 67
Views: 49,035
Posted By vkrastev
Thanks for the hint, now I'm doing some runs with...

Thanks for the hint, now I'm doing some runs with the slip condition for U at the top and side boundaries: I'll let you know if there will be some improvement in convergence patterns.

V.
Forum: OpenFOAM November 4, 2010, 08:32
Replies: 67
Views: 49,035
Posted By vkrastev
Mmmmh, still sounds a bit strange to me (for this...

Mmmmh, still sounds a bit strange to me (for this case, and by my knowledge, it would be quite common to reach a steady-state solution using a standard RANS approach, whether if it is physically...
Forum: OpenFOAM November 4, 2010, 05:21
Replies: 67
Views: 49,035
Posted By vkrastev
Hi neewbie, about the backflow I don't see any...

Hi neewbie,
about the backflow I don't see any trace of it during the runs (the outlet patch is at 5 body lenghts downstream of the body itself: at this distance the flow is again quite...
Forum: OpenFOAM November 3, 2010, 05:29
Replies: 67
Views: 49,035
Posted By vkrastev
This is the residuals pattern after 2000...

This is the residuals pattern after 2000 iterations: indeed, they do oscillate over practically constant values.

V.
Forum: OpenFOAM November 2, 2010, 11:07
Replies: 67
Views: 49,035
Posted By vkrastev
The boundary conditions are described in details...

The boundary conditions are described in details in one of my last posts in this tread but, briefly talking, they are:
-Symmetrycal domain composed by a half Ahmedd model and the surrounding wind...
Forum: OpenFOAM November 2, 2010, 08:52
Replies: 67
Views: 49,035
Posted By vkrastev
PS - I use ANSA as mesh generator

PS - I use ANSA as mesh generator
Forum: OpenFOAM November 2, 2010, 08:34
Replies: 67
Views: 49,035
Posted By vkrastev
Ok, after about 50 runs I have to admit that I'm...

Ok, after about 50 runs I have to admit that I'm starting to get a bit frustrated...Could you please post the fvSchemes and fvSolution dictionaries of a well working case (I mean a case that you have...
Forum: OpenFOAM October 27, 2010, 06:04
Replies: 67
Views: 49,035
Posted By vkrastev
Does anybody think that changing the linear...

Does anybody think that changing the linear solver of some of the quantities (for instance, switching to GAMG for p) would help?

V.
Forum: OpenFOAM October 25, 2010, 11:17
Replies: 67
Views: 49,035
Posted By vkrastev
However, my case is a 3D external aerodynamics...

However, my case is a 3D external aerodynamics case, with a symmetric domain. The domain itself is composed by inlet and outlet sections, the symmetry plane, a floor and top and side patches. I've...
Forum: OpenFOAM October 25, 2010, 04:41
Replies: 67
Views: 49,035
Posted By vkrastev
Hi, Markus if you're talking about the absolute...

Hi, Markus
if you're talking about the absolute tolerances I didn't try such a setting (at most I have lowered the tolerances to 10^-10, 10^-11), but i don't think that it could make some...
Forum: OpenFOAM October 22, 2010, 09:21
Replies: 67
Views: 49,035
Posted By vkrastev
I got your point, but I didn't want to say that...

I got your point, but I didn't want to say that lowering the residuals means to have a less diffusive solution. I was talking about the fact that if one have to reach a really good overall accuracy...
Forum: OpenFOAM October 21, 2010, 13:24
Replies: 67
Views: 49,035
Posted By vkrastev
Hi, ok, I'll try with these new settings but...

Hi,
ok, I'll try with these new settings but let me add some more observations:

- The same behaviour of tke's residuals can be viewed with the URFs set to 0.7: does it mean that even 0.7 is a too...
Forum: OpenFOAM October 21, 2010, 12:20
Replies: 67
Views: 49,035
Posted By vkrastev
Hi Alberto, as I said I've tried to follow your...

Hi Alberto,
as I said I've tried to follow your suggestions, but unfortunately the results were not satisfactory...In particular, I've tried the following new settings:

- URF factors for k and...
Forum: OpenFOAM October 19, 2010, 12:54
Replies: 67
Views: 49,035
Posted By vkrastev
Ok (for both the observations), thanks

Ok (for both the observations), thanks
Forum: OpenFOAM October 19, 2010, 12:52
Replies: 67
Views: 49,035
Posted By vkrastev
Of course linearUpwindV should become...

Of course linearUpwindV should become linearUpwind for the scalars...sorry for the cut-paste error....
Forum: OpenFOAM October 19, 2010, 11:57
Replies: 67
Views: 49,035
Posted By vkrastev
First of all, thanks a lot for your suggestions....

First of all, thanks a lot for your suggestions. About the nonOrth correctors, the 8-option was only a trial to see if there is some significant dependence of such parameter in my case, but actually...
Forum: OpenFOAM October 19, 2010, 10:27
Replies: 67
Views: 49,035
Posted By vkrastev
Hi Alberto, I really need some advices about...

Hi Alberto,

I really need some advices about the convection schemes choice for an external aerodynamics case (hybrid prisms-tetrahedrons unstructured mesh)... For all the details about the case...
Showing results 1 to 19 of 19

 
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