[jamalf64]

Hi Dear Friends
I strongly need your help
I have a geometry that is stirred tank. I want to mesh periodic geometry. but I dont know how should I start? Please give your suggestions.
I attached 4 pictures of my problem: 2 pictures are periodic domain that I want to mesh that.

Thank you so much

[-mAx-]

http://aerojet.engr.ucdavis.edu/gamb...e/mg04.htm#777

[jamalf64]

Originally Posted by -mAx-

http://aerojet.engr.ucdavis.edu/gamb...e/mg04.htm#777

Dear Max
Thank you so much for reply
I can specify zone types but I cant mesh geometry. please help me about meshing strategy.

[-mAx-]

and why can't you mesh your geometry?
Can you point out the warning or errors you got?

[jamalf64]

Originally Posted by -mAx-

and why can't you mesh your geometry?
Can you point out the warning or errors you got?

I can mesh that but mesh quality is low. I do auto mesh(gambit default mesh) by tet/hybrid/Tgrid in inner zone and hex/wedge/cooper in outer zone.

[-mAx-]

max skewness about 0.75 is good, limit is 0.9-0.95

[jamalf64]

Originally Posted by -mAx-

max skewness about 0.75 is good, limit is 0.9-0.95

Thanks in advance
But answers is wrong and I know this is due to the bad quality of mesh.
I've already got the correct answers by Another type of impeller by the same parameters in fluent. Its solution in each time step(10^-3) after every 30 iterations would converge but in this case the solution is converge after 80 iterations in each time step(time step is 10^-6).
I attached 2 pictures of previous problem.

Best Regards

[-mAx-]

and what gives you a check Mesh?
But for sure your skewness is not guilty

[jamalf64]

Originally Posted by -mAx-

and what gives you a check Mesh?
But for sure your skewness is not guilty

Check mesh no problem and its OK

[-mAx-]

Then you don't have problem with mesh.

[jamalf64]

Originally Posted by -mAx-

Then you don't have problem with mesh.

But when mesh quality is low, solution takes too much time. I know that to solve this problem, mesh quality must be high.

Best Regards

[-mAx-]

skewness = 0 means perfekt
skewness = 1 means degenerate

....
http://aerojet.engr.ucdavis.edu/gambithelp/html/users_guide/ug0304.htm#gc_exmesh

[jamalf64]

Originally Posted by -mAx-

skewness = 0 means perfekt
skewness = 1 means degenerate

....
http://aerojet.engr.ucdavis.edu/gambithelp/html/users_guide/ug0304.htm#gc_exmesh

Thank you so much for replies
But I'm not convinced

[-mAx-]

Originally Posted by jamalf64

But I'm not convinced

I will convince you:
generate an awfull mesh with skewness greather than 0.97
Then import in fluent, and do a check mesh

[jamalf64]

Originally Posted by -mAx-

I will convince you:
generate an awfull mesh with skewness greather than 0.97
Then import in fluent, and do a check mesh

I know in this case, the software displays an error message(failed mesh). But when mesh quality is low(not bad) solution takes a lot of time

[-mAx-]

no
the value of your skewness is low, which means your quality is good!
Again:
skewness ~0 means excellent!
skewness ~1 means very poor!

While you compare your both models,what is smallest cell size in both meshes.
And how many cells they have. (cf your post #7)

[jamalf64]

Originally Posted by -mAx-

no
the value of your skewness is low, which means your quality is good!
Again:
skewness ~0 means excellent!
skewness ~1 means very poor!

While you compare your both models,what is smallest cell size in both meshes.
And how many cells they have. (cf your post #7)

My PC is hanging and I dont know why GAMBIT does not run. I will contact you later.

THANKS IN ADVANCE