“…In this respect, first of all, various film-like flows come to mind. They may, for example, occur in tubes, channels or monolithic structures (see, e.g., Levich, 1962;Grossman, 1986;Yih, 1986;Kenig, 1994Kenig, , 2000Boyadjiev and Babak, 2000;Heibel et al, 2001;Killion and Garimella, 2001). Similar possibilities exist for other simplegeometry flows (e.g., cylindrical jets).…”