"Backsplash"
 

Hi - I'm a biologist with NO familiarity with CFD -- BUT I'd like more information on a phenomenon I heard of in graduate school (25 years ago). It's been a useful metaphor, but now I need a more authoritative understanding

I recall the term "backsplash" --referring to that small amount of water in a stream or cascade that moves in a direction opposite to that of the main direction of flow, presumably attributable to irregularities in the stream bed.

(the biological connection: some components of some visual systems MAY be able to selectively perceive such "backwards" flow -- such that the tiny fraction moving in an exceptional direction become a large element in the animal's decision making.)

I'd be grateful for any advice that might point me in the right direction? any simple-minded models?