Taking the curl of a noise field will get you a divergence free flow field[1]... which is an easy way to get something that looks like fluid dynamics, but isn't.

I've use this to great effect on the surface of a sphere to generate textures for gas giants[2]. Some example output: https://imgur.com/a/9LipP

1. https://www.cs.ubc.ca/~rbridson/docs/bridson-siggraph2007-cu... 2. https://github.com/smcameron/gaseous-giganticus