[alemenchaca]

I am modeling a simple cubic room with a small hot plate located at the center of the floor.

In Gambit, I have subtracted the hot plate face from the floor face, defined a radiator boundary condition for the hot plate, and meshed it all. I've first meshed the edges, then the faces (Tri, pave) and finally the volume.

Exporting to a mesh is completed successfully.

However, when I open the mesh on Fluent, I get the following message: "Cannot change radiator.4 [the BC of my hot plate] to radiator because there is only one adjacent cell thread."

I've tried remeshing and rebuilding the whole thing, and I still get the same error.

Any hints on what I've done wrong?

[mbernard]

hello Alejandra

Concerning your issue, why do you use a radiator boundary condition?
Isn't it more simple to get a wall boundary condition, with a surface heat source?

I think the error you got is linked to the boundary condition type. It's the same that for the " interior" boundary condition, that you can't use if your surface is not meshed on his two sides...

Then, you can also check that the surfaces are connected, or maybe tyr to split the volumes instead of substract it...

Did you tick the box " retain" when you substracted your volumes?

let us know about the way it does

Regards

[alemenchaca]

You were right in terms of the radiator boundary condition. (It took me a while to realize that I can define the hot face as a wall, even for radiative properties).
I have defined the plate as a wall in Gambit, and then specified its thermal properties in Fluent.
Thanks a lot!

[mbernard]

hi

I'm glad you managed to define correctly your boundary conditions.
Hope your calculation will give good results

[ershad]

hi
I am simulating a membrane bio-reactor. My reactor has 2 main volumes (Attached file). I subtracted smaller volume from the other, but I retained the subtracted volume.
I have defined 3 boundary conditions as follow:

1. Velocity Inlet (flow of air) : the lower face of smaller volume
2. Pressure outlet: the upper face of bigger volume: it is open to atmosphere.
3. ???I don't know how to define the boundary condition of the upper face of smaller volume. In reality the smaller volume is open from top and the air rise up in the smaller volume and goes out from top of it and enters the bigger volume, At initial, the reactor is full of water and its volume fraction is 1.
I have tried some boundary conditions for the upper face of smaller volume(face2), but I encountered ERRORS as follow:

1. OUTFLOW: "Warning both outflow and and pressure boundaries are present in the domain. This is an incompatibility and solution cannot proceed until this is fixed."

2. INTERIOR: "Error: Cannot change face2 to interior because there is only one adjacent cell thread."

3. INTERNAL: "Error: Cannot change face2 to interior because there is only one adjacent cell thread."

What can I define the boundary condition of that face?
Sincerely yours,
Ershad

[yacprof]

pressure outlet instead of outflow

[syavash]

Originally Posted by ershad

hi
I am simulating a membrane bio-reactor. My reactor has 2 main volumes (Attached file). I subtracted smaller volume from the other, but I retained the subtracted volume.
I have defined 3 boundary conditions as follow:

1. Velocity Inlet (flow of air) : the lower face of smaller volume
2. Pressure outlet: the upper face of bigger volume: it is open to atmosphere.
3. ???I don't know how to define the boundary condition of the upper face of smaller volume. In reality the smaller volume is open from top and the air rise up in the smaller volume and goes out from top of it and enters the bigger volume, At initial, the reactor is full of water and its volume fraction is 1.
I have tried some boundary conditions for the upper face of smaller volume(face2), but I encountered ERRORS as follow:

1. OUTFLOW: "Warning both outflow and and pressure boundaries are present in the domain. This is an incompatibility and solution cannot proceed until this is fixed."

2. INTERIOR: "Error: Cannot change face2 to interior because there is only one adjacent cell thread."

3. INTERNAL: "Error: Cannot change face2 to interior because there is only one adjacent cell thread."

What can I define the boundary condition of that face?
Sincerely yours,
Ershad

Could you manage to solve your problem? Please let me know.
tnx

[yacprof]

for the first question you have to use "massflow inlet" /"pressure outlet" instead of "velocity inlet/pressure outlet"
try it and let me know

[ferra89]

Hi everybody
I am simulating a burner. My reactor has 1 fluid zone (1 Volume).

Exporting to a mesh is completed successfully.

However, when I open the mesh on Fluent, I get the following message: "Cannot change Interiore to interior because there is only one adjacent cell thread."

Interiore consists of the internal surfaces which delimit some blocks and they should be theoretically interior.

I tried imposing or not this boundary condition in ICEM.


How can I do to solve this problem? Please help me!
Thanks a lot

Regads

[mohammad.mohammad]

hi
i am modeling a radiator as porous media zone and for boundary condition i use interior bc
but when i import my mesh file to fluent this error Occurred ""cannot change to interior because there is only one adjacent cell thread""
What I do?