[Sandy7]

Hi Star CCM+ user,

I am trying to find the air flow inside a house model (using stream lines). surface and volume mesh successfully generated and runs fine for first 15 iterations. After 15 iterations, it gives an error " A floating point exception has occurred: floating point exception [Invalid operation]. The specific cause can not be identified. Please refer to the trouble shooting section of the User's Guide. Context star.segregatedflow. SegregatedFlowSolver

I have checked the trouble shooting section but couldn't figure out the reason of this error.

Can some with help!

[Fiedde1887]

Check your mesh for bad-cells, high skewed-cells, bad Quality-cells. There is a macro at Steve-Portal. Adjust your stopping-criteria and your solver Settings. If the case diverge, that can be a reason.

[kirrer]

In addition to the mesh metrics Fiedde mentioned, another common culprit can be the initial conditions, especially if you're applying a pressure somewhere which is significantly different than the initial condition. Try to set initial conditions somewhat close to your final solution.

If that doesn't work, then I recommend you set stopping criteria to 12 or 14 iterations, and review the results at that point in time. Likely you will get some indication of the error - for example, if you have very high velocities or very low densities at some point in space.

Final suggestion, if you are solving air flow in the house, are you using the ideal gas model? That might be adding complexity you don't need. If you want to solve for gravity but you don't expect velocities above 0.3 * c, you can probably get away with a constant density model using the Bousinessq approximation for buoyancy. That would take some instabilities away.

[acalado]

Indeed, check for high residuals, bad cells, or perhaps the initial conditions can be reset or adjusted to ensure convergence