[MechEngr86]

Hello,

I am trying to simulate a cup of water that is exposed to atmosphere above. Eventually I will be adding more complexity, however, I cannot get the water to just sit still. The VOF scene shows the surface developing waves and the Pressure scene shows the pressure freaking out as well. There is no convergence to speak of. Everything I have read on this issue comes back to setting the pressure correctly, however, everything I have tried has also failed. I am using a VOF flat wave to set the water level, and then to set the pressure outlet to the Hydro-static pressure field function populated by the VOF wave model. I also have set the ref. elevation to the free surface, as well as the pressure outlet. I have set the initial pressure to 0 kpa, and Hydro static field function, again no luck. To add to the difficulty I need the water to be variable density cause eventually I will want to look at natural convection, however whether running constant or variable density, nothing works. I have completely run out of ideas and reference material to try. Any ideas? Any other information needed?

Any help much appreciated.

Edit: Directly after posting this I tried turning off surface tension and now the model appears to be behaving. I say appears because I refuse to get my hopes up anymore. Eventually I will need surface tension turned on, any ideas why surface tension would cause the pressure/surface to freak out?

Thanks.

[ping]

sounds like you have used vof wave correctly and i would only expect surface tension to help if your scale is way too small so get the size of the mesh using the ruler or the position field function

what about gravity being enabled and in the correct direction

other ideas - time step small enough, no initial wave nor region velocity, no motions enabled etc