[davidwood]

Hi,
I am having issues with the potentialFoam solver. I have a huge case (almost 80 million cells). When I ran it on a single core, it managed to get some iterations done. However when i decompose the domain into 1200 subdomains, I get nan on the first iteration. My inlet is my own defined velocity profile with random perturbations. This is pre-LES. Is there any reason as to why this is happening. I have searched this forum but i have yet to find anybody having issues with "nan" with potentialfoam. This is for OpenFoam 5.

Thanks
David

[davidwood]

OK. So i solved the NaN issue with potentialFoam by choosing the simple method in decomposePar.
However when i tried to run pimpleFoam, i get NaNs on the first iterations.

PIMPLE: no residual control data found. Calculations will employ 2 corrector loops

Reading field p

Reading field U

Using the loglaw boundary condition
Reading/calculating face flux field phi

Selecting incompressible transport model Newtonian
Selecting turbulence model type LES
Selecting LES turbulence model dynamicKEqn
Selecting LES delta type cubeRootVol
bounding k, min: 0 max: 0.167 average: 0.167
dynamicKEqnCoeffs
{
    filter          simple;
    Ce              1.048;
}

No MRF models present

No finite volume options present


Starting time loop

fieldAverage fieldAverage1:
    Starting averaging at time 0

Reading surface description:
    nearWall

Courant Number mean: 2.78783e-05 max: 0.0216974
deltaT = 1.2e-08
Time = 1.2e-08

PIMPLE: iteration 1
smoothSolver:  Solving for Ux, Initial residual = nan, Final residual = nan, No Iterations 1000
smoothSolver:  Solving for Uy, Initial residual = nan, Final residual = nan, No Iterations 1000
smoothSolver:  Solving for Uz, Initial residual = nan, Final residual = nan, No Iterations 1000

I set prefpoint at the outlet. The case is just a simple wind tunnel experiment with a backward facing step. I am just not sure why I am getting nan on the first few iterations.