Flows
If the water is extensive then the film will flow down any height gradient. The slow viscous flow is laminar, meaning that there should be no mixing, but mixing via diffusion may happen at a very small scale.
Complex Flow: This flow over smooth pavement shows the difficulty of mixing different viscous materials during slow laminar flow. They may wrap around each other, but will they mix? Perhaps the various shades of yellow and green are evidence of very fine mixing. The area was about one meter long.
Erratic and Broken Complex Flow on Pavement: There are only two colorful sections and several very fine blue and dark brown filaments, the latter of which border wider yellow filaments.
Flow Through Gravel Grains: This is flow through the rough gravel-size grains on my paved driveway. One can see flow separation and swirls along the continuous filaments. The area was about 9 cm wide.
Grainy Laminar Flow: The colors remained separated throughout the one-meter length of this non-mixing laminar flow. Close examination will find some recumbency.
Green-Red to Blue-Red Flow: The transition from green to blue may have been caused by the stoppage of one type of hydrocarbon, while red persisted throughout. The area was about 20 cm wide.
Yellow-Blue Flow With Recumbent Folds: Recumbent means folding back on itself.
Yellow-Blue Folds Within Oil Flow: A nice example of recumbent folding. The area was about 13 cm wide.
Yellow-Gray Folds Within Oil Flow
Purple And Yellow Streaks Within Oil Flow: Imaged area was about 5 cm wide.
Yellow-Blue-Brown Mazes Within Oil Flow: Imaged area was about 12 cm wide.