I have been creating small-scale outflows in the lab at Exeter Uni - some of which you can see in the video shown in my post immediately below this one.
This type of flow has many interesting features. We get a chance to observe how ink behaves when it is pulled apart by the increasing spread of a fast outward flow, when it begins to split, often forming irregular, feathered edges. Outward flow caught in a swirl can result in zigzag splits as in "Ever expanding". We also see how ink colours remain discrete; there is no mixing as they undergo their outward flow.
Here are a few examples which illustrate the above: "Wave splitter", "Flyaway", "Ever expanding", "Rococo Waveforms" and "Blue Surf".