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tmeysam92 February 18, 2013 12:02

problem in Fluent
 
Hi all,

i meshed my geometry in ICEM CFD. then i exported to Fluent.

now,i want to have different initial velocity for two parts of my geometry.

what should i do?

thanks in advance.
Meysam.

tmeysam92 February 18, 2013 12:04

someone told me that i should use below way in Fluent:

adapt-region-mark

solution initialization-patch

is it right?

mrenergy February 18, 2013 13:09

I suggest to solve the problem in ICEM not in FLUENT ...

when meshing, give different name for each part and set the boundary conditions you want for each before exporting to FLUENT

also, you can modify the boundary conditions freely for each part in FLUENT

GOOD LUCK

Mamdouh

tmeysam92 February 18, 2013 13:28

Quote:

Originally Posted by mrenergy (Post 408497)
I suggest to solve the problem in ICEM not in FLUENT ...

when meshing, give different name for each part and set the boundary conditions you want for each before exporting to FLUENT

also, you can modify the boundary conditions freely for each part in FLUENT

GOOD LUCK

Mamdouh

thanks for your reply.

i know that i can use icem cfd for bounday condition and i used it for naming inlet, outlet, wall, etc.

my question is about naming a volume, not a surface or edge.

we always select a face or surface in 3d geometry for naming as boundary condition. how can i do that for volume? should i use "create part" tool for volume? how?

thanks in advance.
Meysam.

diamondx February 18, 2013 13:50

In icem cfd , when you click on create new part, look below and choose "blocks", like that will be able to name one block FLUID1 and the other block FLUID2...
Of course this only applies if your mesh is structured

Far February 18, 2013 13:50

With both methods you will get same result. And ICEM method will give you more problems as you have to define the faces on interface of both fluids as internal. If you want two fluids only for initialization then Fluent method is preferable as it does not changes the thing in general.

tmeysam92 February 18, 2013 14:07

1 Attachment(s)
Quote:

Originally Posted by Far (Post 408511)
With both methods you will get same result. And ICEM method will give you more problems as you have to define the faces on interface of both fluids as internal. If you want two fluids only for initialization then Fluent method is preferable as it does not changes the things in general.

thanks for reply.

the method in fluent is easier, but in fluent i should use adapt reging, you know there are three choices for marking a region, hex,cylinder,sphere(look at below picture), now the problem is that my geometry is a nozzle, and its not like those choices.

what should i do?

diamondx February 18, 2013 14:15

hex means the you will mark the elements included in sort of a "box" defined by xmin and xmax, ymin and ymax, zmin and zmax. It's up to you to see the boundaries of that box. if you flow is along x, then xmin means the position of your inlet, until the xmax you wanted to...

tmeysam92 February 18, 2013 14:24

Quote:

Originally Posted by diamondx (Post 408514)
hex means the you will mark the elements included in sort of a "box" defined by xmin and xmax, ymin and ymax, zmin and zmax. It's up to you to see the boundaries of that box. if you flow is along x, then xmin means the position of your inlet, until the xmax you wanted to...

if you look at last post, you will see that i am working on nozzle.

i want to simulate flow in and out of the nozzle, so there is a big cylinder around the nozzle, that the volume between nozzle and cylinder is for simulating the flow out of the nozzle.

now i want to have different initial velocity for just inside of the nozzle , now the problem is that i can not chose a hex or sphere or cylinder, becouse of special geometry of the nozzle.

did you get what i mean??

diamondx February 18, 2013 14:27

i think you can, play with it a little a bit so you can understand how it works, give some random values and hit adapt. then click on manage, and display, you then see the elements that have been adapted

tmeysam92 February 18, 2013 14:32

3 Attachment(s)
Quote:

Originally Posted by diamondx (Post 408510)
In icem cfd , when you click on create new part, look below and choose "blocks", like that will be able to name one block FLUID1 and the other block FLUID2...
Of course this only applies if your mesh is structured

thanks for reply.

i tried to use icem cfd for my proble,.
i am using icem cfd interactive method for meshing. so when it opens icem cfd, first of all i have to choose create block that its name should be "CREATED_MATERIAL",
now when i split the block to two parts, then i use create part like you said, and i named two parts fluid1,fluid2.but the first part,"craeted_material" is vanished and the mesh is not good.(look at below pictures).

diamondx February 18, 2013 14:39

that is just a problem with face association, can you join the project in which you have created those part FLUID1 and FLUID2 let me take a look at it. or just remove face association where the two block meet

tmeysam92 February 18, 2013 14:52

1 Attachment(s)
Quote:

Originally Posted by diamondx (Post 408518)
that is just a problem with face association, can you join the project in which you have created those part FLUID1 and FLUID2 let me take a look at it. or just remove face association where the two block meet

thank you very much.

file is below.

diamondx February 18, 2013 15:01

there you go , as i said problem with association

https://dl.dropbox.com/u/35161486/teysam.PNG

https://dl.dropbox.com/u/35161486/fi...id1-fluid2.zip

Far February 18, 2013 15:21

Quote:

Originally Posted by diamondx (Post 408516)
i think you can, play with it a little a bit so you can understand how it works, give some random values and hit adapt. then click on manage, and display, you then see the elements that have been adapted

Just press mark. With adapt fluent will refine/coarsen mesh.

tmeysam92 February 18, 2013 15:26

Quote:

Originally Posted by diamondx (Post 408523)

thanks very much.

as i told you, because of using icem cfd interactive mood, when it opens icem cfd, first i have to use "create block", and i should name that "CREATED_MATERIAL".the problem is that after creating two new parts,fluid1 and fluid2, the first part(CREATED_MATERIAL) is deleted.
and when i meshed my geometry, in returning back to ansys meshing, it gives me error(because of deleting CREATED_MATERIAL part).
do you know why it happens??

diamondx February 18, 2013 15:29

i'm sure you will find your answer here :

http://www.ansys-blog.com/2012/10/04...d-interactive/

Everything is explained well

tmeysam92 February 18, 2013 15:31

Quote:

Originally Posted by diamondx (Post 408529)
i'm sure you will find your answer here :

http://www.ansys-blog.com/2012/10/04...d-interactive/

Everything is explained well

thanks very much for your really helpful answers.


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