[n7310889]

Hi,
I'm modeling "heat transfer from steel tube to flowing oil" in FLUENT. So I developed a geometry in ANSYS design modeller. I sketched one circle (dia 50 mm) for fluid domain and two circles (dia 50 and 54mm) for solid domain. Then I have extruded them 2000 mm.This geometry I have imported in a mesh component, and developed sweep mesh for both of the bodies independently. Is that okay? Because, if I import this mesh in FLUENT, it creates two additional "WALLS": wall tube and wall fluid. If i set these walls to "INTERFACE", and interface them as FLUID-SOLID interface activating "COUPLED" option, it generates four new walls: two of them are coupled wall, one is shadow and the other is just wall. Using this mesh if I do 1st model in fluent, it does not make any problem. However, when ever I try to reopen the fluent component for the system it says: 'UNASSIGNED INTERFACE" and/or "WRONG ARGUMENT, INVALID THREAD" lub lub. Could any of you please tell me whats going wrong and suggest me, what should I do?

[tmeysam92]

Originally Posted by n7310889

Hi,
I'm modeling "heat transfer from steel tube to flowing oil" in FLUENT. So I developed a geometry in ANSYS design modeller. I sketched one circle (dia 50 mm) for fluid domain and two circles (dia 50 and 54mm) for solid domain. Then I have extruded them 2000 mm.This geometry I have imported in a mesh component, and developed sweep mesh for both of the bodies independently. Is that okay? Because, if I import this mesh in FLUENT, it creates two additional "WALLS": wall tube and wall fluid. If i set these walls to "INTERFACE", and interface them as FLUID-SOLID interface activating "COUPLED" option, it generates four new walls: two of them are coupled wall, one is shadow and the other is just wall. Using this mesh if I do 1st model in fluent, it does not make any problem. However, when ever I try to reopen the fluent component for the system it says: 'UNASSIGNED INTERFACE" and/or "WRONG ARGUMENT, INVALID THREAD" lub lub. Could any of you please tell me whats going wrong and suggest me, what should I do?

Hi,

did you solve your problem???

i have the same problem!!

[tmeysam92]

Originally Posted by n7310889

Hi,
I'm modeling "heat transfer from steel tube to flowing oil" in FLUENT. So I developed a geometry in ANSYS design modeller. I sketched one circle (dia 50 mm) for fluid domain and two circles (dia 50 and 54mm) for solid domain. Then I have extruded them 2000 mm.This geometry I have imported in a mesh component, and developed sweep mesh for both of the bodies independently. Is that okay? Because, if I import this mesh in FLUENT, it creates two additional "WALLS": wall tube and wall fluid. If i set these walls to "INTERFACE", and interface them as FLUID-SOLID interface activating "COUPLED" option, it generates four new walls: two of them are coupled wall, one is shadow and the other is just wall. Using this mesh if I do 1st model in fluent, it does not make any problem. However, when ever I try to reopen the fluent component for the system it says: 'UNASSIGNED INTERFACE" and/or "WRONG ARGUMENT, INVALID THREAD" lub lub. Could any of you please tell me whats going wrong and suggest me, what should I do?

when you import mesh to fluent, go to the interface mesh tab, and create a mesh interface(choose the same interfaces that gives you error as unassigned interface).

i hope it works.
i had the same problem. but i solved it using the method that already told you.

[n7310889]

Hi tmeysam92

Sorry I didn't get you. Could you please explain a little more about (choose the same interfaces that gives you error as unassigned interface)? Another thing is, is it fluid-fluid or solid-fluid interface? Which interface option should I activate? I have activated coupled interface option earlier. Finally, what kind of boundary conditions should I enetr into the auto generated walls, or I don't need to bother with those walls?
I will be grateful if any of you please reply me.

Regards
n7310889

[tmeysam92]

Originally Posted by n7310889

Hi tmeysam92

Sorry I didn't get you. Could you please explain a little more about (choose the same interfaces that gives you error as unassigned interface)? Another thing is, is it fluid-fluid or solid-fluid interface? Which interface option should I activate? I have activated coupled interface option earlier. Finally, what kind of boundary conditions should I enetr into the auto generated walls, or I don't need to bother with those walls?
I will be grateful if any of you please reply me.

Regards
n7310889

Hi,

i attached some pictures of my geometry.

i was working on FSI (fluid structure interaction) problem.

in this geometry i want to calculate temperature distribution in fluid and solid(pipe(fluid part and solid part)).

i meshed the geometry in ansys meshing. then i used named selection for interfaces between fluid and solid(FIG1).

when i import the mesh to fluent, and i use CHECK button, it gives UNASSIGNED error(like FIG2).

I used MESH INTERFACE tab in fluent. then i chose the solid and fluid interfaces. (FIG3).

know there is not error, if use CHECK button.

if you do the same thing that i did, i think your problem will be solved.

my English writing is not good. sorry if i made mistakes.

[tmeysam92]

one more thing.

is your geometry a pipe or like a pipe??? if yes, why do not you use this way,

ansys design modeler- CREATE-primitives-cylinder