gambit mesh "T" tube
 

hello everyone,

i am a beginner of gambit. now i am trying to creat a mesh on a "T" form tube. do you have some ideas pr suggestions about how to seperate the different parts?

thank you

you are not enforce to decompose your domain, execpt if you want a full hexa mesh

i have used fluent to calculate, it showed that there were instability at the entrance of the small tube. so i have no choice to seperate the interval part to have a more precise part. but i always get a great number of mesh.

post pictures, and explain your boundary conditions

Hello , this is the tube that i use,.
The boundry conditions are : turbulence with a velocity of 5m/s inlet.
Flow rate weighting 0.5 ; 0.5
http://www.cfd-online.com/Forums/dat...AASUVORK5CYII=

i don't knoz how to add pictures, to i make a link here. thank you
https://www.dropbox.com/s/s1ufa02vv9oka4k/0625.docx

I don't see pictures
What kind of BC did you use for outlet?

you have to go in advanced mode

please post picture with focus on your mesh, else we don't see anything.
Pleas post also picture of velocity and pressure distribution

this is the document; https://www.dropbox.com/s/5oqvv81gvb...0question.docx

sorry for making you waiting so long, i am not used to the computer with the french keyboard that i use.

ok can you display clother at the T junction, especially velocity distribution. Something sounds weird left to the T junction.

Regarding to the mesh, you seem to have splited your domain, right?
Can you also list all the surfaces with their BC, I see lots of surfaces

And finally when I see the the velocity distribution, I assume your inlet is the pipe with smaller diameter. But if it is exact, then the pressure distribution is wrong

can you provide me your dbs file from Gambit? (delete the mesh for reducing file size)

https://www.dropbox.com/s/nsfn9id1k1...lageRe10-5.dbs
here it is, there are some changes, i didn't save that version.

ok, seems to be ok, but you don't have any surfaces in the BC.
I assume you fixed the problem.
Other point: what are your dimensions m,mm,... ?

the dimensions are mm. and in fact i am a beginer of fluent and gambit, i don't know which faces to add with BC

ok, did you scaled your domain in fluent?
Gambit doesn t have any dimension.

ok, i find that i am totally fool, i thought the dimension was set by default as mm. i just searched the user's guide, it's set as Meter. however, i didn't scale the dimension

you have to scale your domain:
in your case, select mm, and then click on scale
If you have a diameter of 20, Fluent will understand 20m
If you scale it, Fluent will convert and undestand 20*1e-3 = 0.02m

Once it is done, do a check mesh, to be sure that your mesh is ok.
Then compute.

OK, thank you very much. i think i have to rebuild the mesh as the skewness exceeded 0.98