Stopped in routine ENFORCE_BOUNDS
Briefly before Christmas I have a CFD Problem...
Maybe anybode can help me:
I am doing a transient simulation with cavitation. First I have made a transient simulation with cavitation turned off as initial guess. Now I have turned on cavitation and the solver explodes after a few Iterations. I get pressure values of about 300 bar, which causes my solver to abort.
See the Outfile Below:
Some Details for my Case:
- reference pressure: 0 atm
- timestep: 5.5e-5 s
- inlet: total pressure
- outlet1: opening
- outlet2: pressure outlet
Any Hints appreciated! Thanks in advance
More Details required?
Your simulation is not converging well. Need to improve the numerical stability - smaller timesteps, better mesh quality and check the physics.
I have double checked the mesh quality, it is quite well:
Minimum Angle > 27°
Determinant > 0.5
I decrease the timestep to nanoseconds (which is a valuable size for cavitation problems) and see after christmas if it helped.
Here some details for my cavitation model:
- Rayleigh Plesset
- Mean Diameter: 2e-6m
- Saturation Pressure: 0.02 bar
Mesh quality requirements are different for different physics models. The rules of thumb for single phase flow are often not appropriate for multi phase flow. I would spend some time to get the mesh as good as you can in the area of cavitation as it will pay dividends with improved convergence, better accuracy and reduced run time.
I would use adaptive time stepping to let it find its own time step size.
Hello Everybody and a Happy new Year!
I´ve got my case running, it was a false Expert Parameter Setting, I had:
solve volfrc = f
Setting this parameter to true, keeps the solver running. But Convergence is still bad.
Anyway now I am facing a real annoying problem:
My outfile clearly states to write Pressure to Transient file:
Has anybody a solution for this stupid problem?!
Your expert parameter turns the solving of the volume fraction equation off. You are not going to get far when you are not solving the equations.
I have no idea why pressure is not in the output file.
There is pressure in the out files indeed.
But I have to choose Solver Pressure instead of Pressure. This comes with the cavitation model. Its explained in the User Help
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