GAMBIT : Pipe with multiple holes
 

I am a new user and trying to make geometry for a burner. It is a simple 1" dia pipe with 14 1/8" holes on its side.

I have tried much, but always failed to make this geometry in gambit.

What I do is that I make a cylinder using volume command and then make several circles using creat face at its side.

If I project these faces on the volume, it creates virtual curved faces on side of volume... BUT the desired muliple faces are not created which can be prperly meshed and assigned boundry conditions.

How should I make this arrangement ?

Thanks... MML

Re: GAMBIT : Pipe with multiple holes
 

use cylinders instead of circles and get the intersection,

Re: GAMBIT : Pipe with multiple holes
 

Thanks for the suggestion.

I just did that (intersection of cylinders). But that resulted in totaly a different thing!.

I made one horizontal cylinder and one verticle cylinder which started from horizontal cylinders center and protruded from its side.

After intersection, All I was left with was a part of verticle cylinder! all else was deleted.

The requirement is to make a pipe with multiple holes on its side.

Thanks for your kind help.

MML

Re: GAMBIT : Pipe with multiple holes
 

you should have merged two volumes then you have a single combined solid, create another cylinder and split the one you created with this cylinder and you will have two different cylinder, if you don't want to keep the protuding part, just delete it,

(use unstructured meshing to mesh this)

It should be something with "Retain", Bidirectional and Connected buttons... But I don't remember very well...

Could anyone give me a tip?
Thanks

Hello, again. Finally I made the holes. I want to share this with you. Maybe some of you will face the same problem and will want to try my solution.

-Create Cylinder1 (pipe)
-Create Cylinder2 (hole)
-Move Cylinder2 in the position (the intersaction of 2 cylinders will be the hole creted by us using this method)
- Split Cylinder1 with Cylinder2 (Retain, Bidirectional selected)
- Unite the Cylinder3 (creted after spliting) with Cylinder1
- Split the big cilinder (initial Cylinder1) with the outside part of the small cilinder (initial Cylinder2)
- delete the parts that you do not need

You will remain with a hole...

Good luck.
I encourage you to post some of the solution you find at the problems you face with and you find solutions.
Best regards.

your way seem too complex to do it.
can you just use the "intersect" and retain everything then delete those u don't need.

OR

u just "subtract" with cylinder 1 on top column and cylinder 2 as 2nd colum and retain the cylinder 2.

I think 2 way above should create the same result.

so i have a similar problem as above. its a combustion chamber and i need to add dilution holes, which will later have mass flow boundary conditions attached to them.

i simply created cylindrical volumes going through the main combustion chamber, and then subtracted these to give me the holes i need.

my question now is how can i specify what boundary conditions are attached to these holes? in gambit, the boundary conditions can only be attached to faces/edges/groups, and as far as i can tell, the holes dont fall under any of those categories.

picture plz.
 

can you post up some picture so i can understand ur question?

okay, the files are attached, sorry for the poor quality.

in view2, you can see how i made the holes, by having cylindrical volumes through the main combustor and then subtracting these. view1 shows the final result.

my question is - in gambit, these holes are not defined as edges, so i cannot apply boundary conditions to them, which i need to do. so is it possible to now go back and define them as edges?

or can i just leave them, and define boundary conditions for them later in fluent?

are u saying the cylindrical volume have some pipe poke thru into it and supply liquid?
From what i saw in ur modeling, u should click retain while u do subtract so the pipe u model will remain there.
After that u have to create interface between the end of the pipe to the cylindrical volume.

Post up a picture of the close look of ur holes.

attached is a close up of the holes, hope it helps.

but i think you're right. the cylindrical volume has flow going through it from one end to another. but the holes are an additional inlet, adding more air flow.

ill change the model. just, quick question. when you say create interface, you just mean create a face from the circular edges right?

Hi, everyone
I wanna know how to make a hole on a spherical surface for an injection in fluent? Do I even need to create a hole manually for an injection?
Thanks

hi my friend
is it possible for you to show me how do you mesh your geometry?
I have faced such a problem like yours.
thanks a lot...