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This parameter is defined as mass per volume unit and is different for each substance. “Density” does not change the fluid's behaviour, but it is possible to mix fluids from different domains. This way you are able to simulate substances like oil and water. The unit is kilograms per cubic metre. The density of water is 1,000 kg/m3. Avoid very small values close to 0, because they can lead to instabilities.
Int Pressure
Internal pressure
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“Internal Pressure” simulates the forces between nearby particles and pushes them apart - this makes the fluid fill a greater volume.
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Ext Pressure Scale
This parameter tries to limit a fluid’s expansion tendency and can be compared to atmospheric pressure. Particles tend to "stick" together with higher values. The substeps and iterations settings in the "Scene" node's → "Solver" tab influence how this parameter acts on the fluid.
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