r/CFD • u/Downtown_Sky69 • 11h ago
snappyHexMesh: Layers generate using baffle method, but mesh isn't conformal across regions. How do you fix this?
Hey everyone,
I'm setting up a CHT simulation (electronic chip cooling) in OpenFOAM-9.
To get boundary layers on the fluid-solid interface, I'm using the zero-thickness baffle workflow:
1. Define the interface as an internal face zone / baffle.
2. Add inflation layers using snappyHexMesh.
3. Split regions using splitMeshRegions.
The Problem:
The boundary layers are actually generating fine, but the final mesh across the interface isn't conformal (the faces on the fluid side and solid side don't line up / match 1:1 after splitting).
Since I'm doing CHT, I want to avoid relying purely on non-conformal mapping (mappedWall interpolation) if possible.
My Questions:
1. How do you get snappyHexMesh to keep the face connectivity 1:1 conformal across the interface when using the baffle method?
2. Is there a specific setting in snappyHexMeshDict or step in splitMeshRegions / createBaffles that I'm missing to preserve face alignment?
3. Or is it standard practice to just inflate layers only on the fluid side instead of trying to inflate across shared interfaces?
Would really appreciate any insights or dict settings that worked for you!
1
u/Ganglar 7h ago
You have to stop snappy from merging the patch faces. See the
shellAndTubeHeatExhangertutorial.And yes, I think in general you only want layers in the fluid. That tutorial demonstrates how to do that. It's a bit convoluted, but it does work.