[Ben0000]

Hello, I've made a model using snappyHexMesh to create the mesh for a building and the air domain surrounding it, but I'm having difficulties with getting the model to run. I believe the issue is with the size of interface between the solid and fluid domains. When I ran the model with interfaceTransferMethod directMap, I got up to the following lines in the log.

additionalMeshCorrection: false
Selecting interfaceToInterfaceMapping directMap

At this point the program doesn't progress any further, I left it running at this stage for ~8 hours before terminating it.


Next I tried interfaceTransferMethod RBF. This resulted in:

additionalMeshCorrection: false
Selecting interfaceToInterfaceMapping RBF
Time = 0.001

Setting traction on solid interfaces
Interpolating face values using RBF
Create RBF interpolator from fluid_to_solid to solid_to_fluid
terminate called after throwing an instance of 'std::bad_alloc'
what(): std::bad_alloc
ERROR

Finally I tried interfaceTransferMethod GGI, this resulted in:

additionalMeshCorrection: false
Selecting interfaceToInterfaceMapping GGI
Time = 0.001

Setting traction on solid interfaces
Interpolating face values using GGI
Create GGI zone-to-zone interpolator
interface-to-interface face error: 0.0237136
calcMasterPointAddressing() const
Extended GGI, master point distance, max: 0.325573, avg: 6.52438e-07, min: -0.331222
interface-to-interface point error: 0.331222
Number of uncovered master faces: 0
Number of uncovered slave faces: 0

Total force on fluid interface 0: (0 0 0)
Total force on solid interface 0: (0 0 0)

Evolving solid solver
Solving the momentum equation for D
setCellDisplacements: reading cellDisplacements
Corr, res, relRes, matRes, iters
ERROR

The program ran for about two hours after the second-last line, before outputting "ERROR" and stopping.


I'm thinking that the size of my model might be the issue, looking at solid/polymesh/boundary, the solid_to_fluid patch is defined as:

solid_to_fluid
{
type mappedWall;
inGroups List<word> 1(wall);
nFaces 4445923;
startFace 22265720;
sampleMode nearestPatchFace;
sampleRegion fluid;
samplePatch fluid_to_solid;
}

And similarly, in fluid/polymesh/boundary, the fluid_to_solid patch is:

fluid_to_solid
{
type mappedWall;
inGroups List<word> 1(wall);
nFaces 4445923;
startFace 32173810;
sampleMode nearestPatchFace;
sampleRegion solid;
samplePatch solid_to_fluid;
}

Given the large number of faces these patches have, I was wondering if there is an issue with how much memory is required. Watching the program whilst its running, my ram usage stays around 95%. Is there anyway to estimate the ram required for the ~4.5 millions faces? Also, does anyone know why the number of faces is not equal between the two patches? I modeled both the solid and air domain using a single snappyHexMesh, and then used splitMeshRegions to split the mesh into a fluid and solid domain. I did this as I thought it would make the two meshes conformal, but perhaps not? Thanks.