Why is my mantaflow liquid acting like it’s falling on a flat surface when it’s not

Hi jesse, the Scale  your resolution is too low. Always scale your Domain in Object Mode and then Apply the Scale (that will ensure the the voxels used for the resolution are cubes and not ‘stretched, like in you case; see bottom left in the Domain),

And the set your resolution so high that the voxel size is small enough for your liking. (Notice how the distance from the liquid to the walls is exactly one voxel…)

(I know! Physics Simulations can be sooo frustrating; you have too get everything right, but after doing it enough, it will become second nature and the results can be quite spectacular!)

Sorry this took me so long, but apparently it is normal to have a gap between the liquid and the Domain; here is a picture from the Blender Manual where you can clearly see the gap:

Look at the little squares (bottom left of each fluid). They are at the corner of the Domains and show the size of each ‘cell’/voxel.

So: increase the size of your Domain, until it fits. Or move the floor up a bit until it touches the water…(I don’t think you care about the sides…)

BTW: applying the scale of your Domain will make the voxel size smaller, maybe your computer can handle that…

Domain in green, look at the orange square:

The distance from the liquid to the domain is ‘normal’.