Simulation error after a couple of frames

[ben_hamburg]

Hi there,

I´m having trouble with a simulation right now: I have a relatively fast moving boat and after about 40 frames into the simulation I noticed my splashes were kind of "exploding".
First I thought it might have to do with birth rate beeing too high or threshold too low, but then I realized that the error was starting in the fluids: from one frame to another I had a huge build up that shoudln´t have been there (no big collision or anything happening at that frame)
So I tried upping the SPS and played around with the grid size, but the problem persisted.
Right now it seems to be working.
What I did was: Instead of starting the simulation from the beginning I restored it from a couple of frames before the error appeared and I also disabled the viewport preview of foam and splashes. I also hid a animated and cached character standing on the boat, in case the error was due to memory or not enough processing power, but I don´t think that was the issue.

Have you ever encountered anything like that?
Right now it seems to be working, but in case the whole simulation runs smoothly, I´d still like to know what caused the problem.
Unfortunately I already overwrote the cache file, but If you would like to investigate I could just send you a stripped down scene file.

[Ivaylo Katev]

the main cause for such issue is a small cavity in the geometry, you know our old submarine scene, before we having it working we encountered this problem twice, because it was a hole in the geometry and it caused huge jets of splash like a whale.
disable the splash in the preview and see how looks the liquid at the instability point. would be good if you attach some images showing the instability and a closeup of the geometry where it appears

[ben_hamburg]

Ah, yes, now I remember having had that issue with another sim before. In that case the hole was very obvious, but since it was on top of the boat I figured it wouldn´t be a problem. But of course it was...
I used the same mesh before without problems, but I´ll check again, it might just not have been a problem because it was animated differently last time.