#polymer effects

Adding just a little polymer to a pipe flow speeds it up by reducing drag near the wall. But the effects on turbulence away from the wall have been harder to suss out. (Image credit: S. Wilkinson; research credit: Y. Zhang et al.; via APS)

Active nematic fluids borrow their ingredients from biology. Using long, rigid microtubules and kinesin motor proteins capable of cross-linking between and "walking" along tubules, researchers create these complex flow patterns. (Video and image credit: G. Pau et al.) Read the full article

Decades ago, engineers pumping polymer-filled drilling liquids into porous rock noticed sudden and dramatic increases in the viscosity of the liquid. Within the tiny pores of the rock, conventional (i.e., inertial) turbulent flow should be impossible -- the Reynolds number is simply too low. Now a new experiment points to the source of the high viscosity: elastic turbulence. (Image credit: top - M. van den Bos, pore flow - Datta Lab; research credit: C. Browne and S. Datta; via Quanta Magazine; submitted by Kam-Yung Soh) Read the full article

The Venus flytrap snaps shut on its hapless prey by swelling cells in its leaves with water. Researchers are using similar physics to create jumping and snapping polymer gels. (Image credit: plant - A. Dénes, shell - Y. Kim et al.; research credit: Y. Kim et al.; via Physics World)

Find out the answer!