Making an object invisible under fluid flow

Phys.org  January 7, 2022
Without any obstacle, the fluid flows along a straight line. If an obstacle is present, the straight streamline will be defected, and an observer can sense the size, shape, and position of the obstacle. Guiding the fluid to flow faster closer to the obstacle and slower farther from it conceals the distortions and restore original straight streamlines. Instead of engineering the mass density of the fluid to control the speed of the fluid flow, researchers in Singapore simply engineered the thickness of the fluid channel. They showed that thicker fluid channel gives rise to smaller mass density, where the fluid flows faster. Hence, a large-scale invisibility cloak can be implemented by simply making the fluid channel thicker closer to the obstacle and thinner farther from it. They successfully demonstrated their technique of fluid cloaking without the use of metamaterials…read more. TECHNICAL ARTICLE 

a. The fluid-flow cloak guides streamlines smoothly around a cylindrical obstacle… Credit: Science China Press