The German word for these patterns is "Schliere, pl. Schlieren", and apparently this word has entered the English language as a loanword (cf. article Schlieren in Wikipedia or entry schliere in OED). But the German loanword is probably not something most native speakers of English understand without the help of a dictionary, so what would you call, or how would you describe, the following patterns?
Oil on water:
Coffee and milk:
And so on.
"Waves" is not applicable, because waves are vertical undulations of the surface, while these are a pattern on, or inside, the surface level, with no amplitude.
"Striæ" does not really fit either, because those refer more to the parallel layers, than to the curly forms.