Hello,
I am trying to model a solar cyclone tower (Article The solar cyclone: A solar chimney for harvesting atmospheric water
) in Fluent. At the moment, I am trying to model a simplified version without the vortex to try and get the simulation of the evaporation/condensation working. To help get me going, I have looked at similar simulations of solar distillers.I am running into a problem with my setup that I have so far been completely unable to remedy. The console prints:
5 1.0000e+00 2.0316e-01 3.8673e-02 3.8433e-02 1.8664e+29 1.0000e+00 2.2538e+08 1.5620e-01 1.3353e-01 0:19:53 45
Error at Node 3: floating point exception
Error at Node 0: floating point exception
Error at Node 1: floating point exception
Error at Node 2: floating point exception
turbulent viscosity limited to viscosity ratio of 1.000000e+05 in 13594 cells
Stabilizing temperature to enhance linear solver robustness.
Stabilizing temperature using GMRES to enhance linear solver robustness.
Divergence detected in AMG solver: temperature Stabilizing vof-1 to enhance linear solver robustness.
Stabilizing vof-2 to enhance linear solver robustness.
turbulent viscosity limited to viscosity ratio of 1.000000e+05 in 13591 cells
Divergence detected in AMG solver: temperature
Divergence detected in AMG solver: temperature
Divergence detected in AMG solver: temperature
Error at host: floating point exception
===============Message from the Cortex Process================================
Compute processes interrupted. Processing can be resumed.
=============================================================================
Error: floating point exception
Error Object: #f
From what I have been able to find online, this kind of error is usually attributed to improper meshing leading to a divide by zero. However, I have checked the mesh and everything seems fine there.
Has anyone got any suggestions on how I can attempt to troubleshoot this problem.
Thanks.
Hi,
if such numbers occur in your residual summary:
1.8664e+29
than the solution has been diverged already for a long time. The concrete error might be completely unrelated to its original source/origin. You need to analyze your complete CFD setup for any kind of inconsistencies in models, contradicting boundary conditions and the like. And most likely the solution simply diverges. Reason might be : bad mesh, too large integration timescale/timestep, wrong or not goal-leading parameter settings of numerical models,....
Impossible to judge for the correct reason from the distance.
Regards,
Dr. Th. Frank.
Try to use the method where you could control the time step between iterations. Maybe use a transient solver ...
Floating point can mean a divide by zero is occurring somewhere. Check the mesh quality (skewness under 0.8) and also the boundary conditions & models.
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