laplacianFoam blow up
 

Hello all,

I am struggling with a laplacianFoam case, with just a simple heat transfer case. I have built a mesh in Salome and exported it fine into openfoam,
Settings are:
Transport Properties: DT = 19e-5
System settings are as tutorial
T values:
inlet = 773K
outlet1 = zeroGradient
outlet2 = zeroGradient
defaultFaces = zeroGradient
Walls = $internalField (273K)

I run the case for 100000 steps and for the first 50,000 or so the simulation runs as expected. However, after that it starts going crazy and temperature goes exceedingly high towards the end. I've attached some screenshots and also of Surface with edges to show what the mesh looks like. dz is 0.01.

Any ideas why it begins to blow up? Surely the temperature should leave the outlets?

Thanks,

Rapha