I am trying to work out how to apply say a blue ink being dropped into a glass tube that has water in it, but the tube is not straight, and is more like a bendy straw...

But I can not get the 3D Fluid emitter to work just within the object, I have tried setting the emitter to volume, but all that doies is create a smaller box emitter within the 3D Fluiod emitter and that does not seem to work either.

Any ides would be VERY appreciated, I have lost 3 days sleep trying to work this one out.