Turbulence
Noise folded back on itself so it swirls with sharp creases, like smoke or fire.
See it in Noise & texture. Set the noise type to Turbulence, then raise Octaves for finer creases.
In plain words
Smooth noise rises and falls gently on both sides of a middle value. Turbulence flips the low half up, so every dip becomes a sharp crease. Stacking several layers of it gives a busy, swirling look. It looks like smoke, flames and stormy water. In moving tools, turbulence is also a random push that makes particles wander.