create mixing tank in gambit
 

-create your tank as solid
-create your impeller as solid
-create the bouding box surrounding all your solid elements
-substract tank and impeller from box
Now you have the fluid domain
Split your domain for being able to pick your moving zone (or setting it as moving fluid)
Mesh

Dear mAx
Thanks for reply
I dont understand.
Bouding box surrounding all solid element?
Tank is largest cylinder.
please describe to me in detalis.

Best Regards
Reza

I already described in detail.
If you build the tank and the impeller as solid, you are ready to compute stress analysis in your solids.
But you want to compute flow analysis. So you need to mesh the flow domain.
For that you need to extract fluid domain from solid. So you create a big domain (fluid), and you substract all you solid parts

Ok

I know that for use MRF, we must be 2 domains, first is rotating domain and another is stationary domain. rotating domain is a bounding box around impeller(cylinder).
Which one is your purpose to souronding box?
I create three volume:tank, impeller and bounding box around impeller. I dont know how do subtract or split or others command,now.


Thanks in advance
Reza

don't mix the steps.
Bounding box is only here for extracting your fluid domain.
Once it is done, you do your split, and it divides your fluid domain into 2 subdomains: stationnary and moving.
That's all

I confused :confused:
please forgive me.
Bounding box is large tank(main tank that we want to compute fluid flow in it), yes?

No bounding box is a volume you will need to create the fluid domain.
I give you an example: you will compute flowfield around a cylinder (von Karman)
You create the cylinder as solid. But you need the fluid domain around the cylinder. So you create an outer box (bounding box), and you will substract the cylinder from this box.
As result you get the box BUT with the cylinder as hollow.

Dar mAx
thanks in advance
your mean is a thing similar to wind tunnel. ok?
but what is size and boundary condition of bounding box?
diameter of tank is 0.3m
radius of impeller is .045

Best Regards
Reza

Bounding box, will disappear once you created the fluid domain. So it won't have any BC
Post a picture

hi reza
i am iranian
if u want u can contact me by this address .i think that i can help u.
behrooz_afra1990@yahoo.com

Hi Behruz
Thank you so much, I do it.

Best Regards