Simulating anything can be tricky. Simply for the fact that it can be difficult to get things the way that you want. We all have a picture in our heads, that we are trying to get to, and although dynamics and simulations can be art directed, there are times when you might not get what you want. This can also be the case when using a fluids-based system, like TurbulenceFD.
Getting fire or fluid simulations to act the way you want can be a little tricky to say the least
Thankfully, if you are just getting started, Voxyde can help you out. Here, Voxyde shows how you can set a skull on fire, using Cinema 4D, TurbulenceFD, and After Effects for compositing. If you are getting started, this is a good walkthrough to get you centered with TFD. IT covers all the important parameters, and how to adjust them to get what you re looking for in a simulation.