[main]

hi I try to simulate the square ribs in duct in quasi 2 dimension.
I generate the geometry of duct using block mesh and using stl file I intended to inplement the square ribs and then generate mesh with sHM.
After commanding sHM in terminal i got this geometry (see attatched picture error)
What i expected was like in file (squareribs)
You can see the ribs doesn't fit what i made in stlfile.
Does anyone know what is the problem?

[Yann]

Hello,

Just to make sure, have you run snappyHexMesh with the -overwrite option? If not, have you moved to the last timestep in ParaView to visualize your mesh?

I'm suspecting your screenshots could show the castellated mesh and not the snapped mesh.

Yann

[main]

Thank you for your reply. Yes I realized the process is not finished yet. But I finished now. And I have new question do you have any tips to combine the boundary? Bc I want to give the heat on the bottom so that I can see how efficient the ribs depending on the shape. Since I set the block mesh as a duct and ribs using snappyhexMesh, I have teo boundary for heated wall. How can I combine or redefine the boundary?

[main]

I am considering now with toposet btw… Is it possible with toposet?

[Yann]

Yes you can do it with topoSet.
Or just define the boundary condition you want to use on both patches.

[main]

Thank you!

One more question about the 2. option.
So if I group the bottom wall from block mesh and the square ribs in boundary condition and give the heat flux in vertical direction, then the heat flux is automatically applied on surfaces of the square ribs and bottom wall except for where the ribs exist?

[Yann]

What boundary condition do you intend to use?

[main]

I always thank you yann for helping me!!
Using externalWallHeatFluxTemperature constant heat flux. I just tried to group the wall where the heat is applied (bottom wall and square ribs) using createpatchdict. Because the bottom wall I defined by blockMesh is removed automatically where the squareribs exist. But I realized that the heat isn't applied at all on the squareribs in this way.
So I undo the grouping the both boundaries. During running the simulation I check the heat flux value using wallHeatFlux (postprocessin utility) on the bottomwall and it doesn't correspond to the value I specified... less than what i gave...

Is there any other way to apply both boundaries equal value of heat flux?

[Yann]

Hello,

I'm not sure what is going on, but I think whether you have one single patch or several patch should not matter, both should get the specified heat flux once the solution converged. (did it?)

Originally Posted by main

I just tried to group the wall where the heat is applied (bottom wall and square ribs) using createpatchdict. Because the bottom wall I defined by blockMesh is removed automatically where the squareribs exist. But I realized that the heat isn't applied at all on the squareribs in this way.

I'm not sure what you did, but it sounds like something was wrong with your patches if you didn't have any heat flux on the square ribs.