Fluid failing to enter side channels in Blender 2.80 fluid simulation I have a fluid sim under Blender 2.80 which requires liquid to flow into a main structure and fill side channels off (imagine underground passages flooding or a storm drain backing up).

Past a certain relative width, I cannot get the 'liquid' to flow into these smaller side areas, even with a lowered viscosity; all the fluid does is gain height, as the level behind rises, and inch forward rather than flow in. The relative width of the side channels seem to be important as I've sized a test area to 5m x 5m, then magnified it to 50m x 50m and still have the same difficulty (Transforms applied, afterwards).

Having been through boundary type settings, viscosity settings, domain height (less volume is not necessarily better) and one or two other options (3am never is a good time to still be working, let alone remembering) can anybody suggest other parameters which will allow the simulation to unfold as hoped? A much higher resolution? Boundary subdivisions? Animal sacrifice?

I've reproduced the effect in the attached test file.

Thanks,
Quin.
First, in the Domain options Set Boundary to Free Slip. With just this change in the file you attached I got as far as this:



You could probably play with subdivisions / surface smoothing or make the timeline longer. It might also help to make the domain only as high as the obstacle, so the fluid doesn't overflow before filling the smaller channels.