Hmm. Not my area of expertise but example one is using fluid dynamics. If you search around here you will see some examples of that in both 2D and 3D. There will be a little bit of theory explained around here too but it might be advisable to try out the implementations, take a quick look under the hood, break stuff, and look at some elsewhere for a theory of how the parts work together having familiarized yourself with the implementation. Can anyone else recommend some good literature on this subject?
Example two is using the almighty fieldtrip.