July 19, 2017, 10:51 a.m.
The liquid part of the mud should be achievable with the right viscosity + density settings. You might have to experiment with the sludge component however. Since it doesn't really behave like a fluid you might need to use grains.
Are you able to provide an example file? I would be happy to take a look and offer some help.
Surface tension is applied through a field named “surfacepressure”. You can manually modify this field through the “Volume Velocity” input in the flipsolver.
For example, you could set an attribute on the particles to represent surface tension. Then use Gas Particle to Field to bring it into a field context and then scale the surfacepressure field by this newly created field. This will give the droplet and the tank different surface tension strengths. However once your droplet collides with the water in the tank, you will end up with a strange blend of surface tension strengths.
Hope that helps,