Braiding patterns on an inclined plane

Abstract

A jet of fluid flowing down a partially wetting, inclined plane usually meanders but--by maintaining a constant flow rate--meandering can be suppressed, leading to the emergence of a beautiful braided structure. Here we show that this flow pattern can be explained by the interplay between surface tension, which tends to narrow the jet, and fluid inertia, which drives the jet to widen. These observations dispel misconceptions about the relationship between braiding and meandering that have persisted for over 20 years.

Particle image velocimetry and modelling of horizontal coherent liquid jets impinging on and draining down a vertical wall

“…by Mertens et al, 2004). Cartesian co-ordinates are again used in Zone IV: x is the distance downstream from plane BB; y is the lateral co-ordinate, directed to the right; the local half-width of the film is w.…”

“…It should be noted that the location of maximum width also depended on the flow rate, moving further down the plate as Q increased. Mertens et al (2004Mertens et al ( , 2005) used a long plate to be able to capture the distance to the node: as the primary interest of the present study is on cleaning and the area contacted by the liquid in the jet, this is not considered essential here. Figure 10 shows the effect of mass flow rate on the film flow behaviour on Perspex substrates.…”

Peptide hormones and lipopeptides: from self‐assembly to therapeutic applications

“…PYY (3–36) was injected into fasted (for 24 h) rats' hypothalamuses, and this led to a significant decrease in food intake, even at doses as low as 100 μg kg −1 145. This effect was initially controversial with very few other researchers being able to repeat the result 146. A theory behind the controversy was proposed, this being that the mice used in the repeat tests were unaccustomed to the laboratory environment, which increased their stress levels.…”

“…A theory behind the controversy was proposed, this being that the mice used in the repeat tests were unaccustomed to the laboratory environment, which increased their stress levels. Stress inherently reduces baseline food intake so it makes any investigations in anorectic agents difficult to assess 146. Further research into the use of PYY (3–36) in human studies has found that obese subjects show normal levels of sensitivity to the appetite‐reducing effects 147.…”

Meandering of a particle-laden rivulet

“…Sediment transport was believed to be necessary for flow meanders [12], however, experiments without sediment transport also manifest meandering [8,10,13]. While the notion of meandering as an inherent global flow instability that arose in the 1980s [13] has been experimentally disproven [6,7], transverse shear stress distribution along the wetted perimeter of the meandering stream [14] likely still plays a role in meandering. It is also notable that, in the case of natural flows, their course can also persist for a long duration.…”