Flowery Flow: A Fluid Dynamics "Poppy" Captures Prize
An image that conjures an Andy Warhol painting of a poppy received honors in a contest sponsored by the American Institute of Physics. Concordia University in Montreal engineer Hoi Dick Ng and his student Anna Chtchetinina created the image and entered it into the annual AIP competition for the best entry related to fluid dynamics, the science of how liquids and gases move. Their photo was one of twelve winning posters and videos in the Gallery of Fluid Motion.
The experiment involved a tank of water with a cylindrical gate lodged in the middle. The water level inside the gate was lower than the water level in the rest of the tank. When the gate was removed, a high-speed camera captured the implosion of the exterior region of water as it rushed to equalize height with water in the rest of the tank. The camera, poised below the tank, snapped black-and-white photos, which were later colorized. The colors are based on the darkness of individual pixels and roughly correspond to the shape and height of the water's surface. The red, poppy-shaped region represents water flooding into the center from the initially higher outer parts of the tank.
Ng researches the dynamics of shock waves: supersonic jets, meteors crashing to Earth and so on. For safety reasons, researchers model these violent phenomena with water.
The authors acknowledged the symbolism of the flower they created: "Artistically, the implosion core resembles the shape of a remembrance poppy," they wrote. Since the 1915 publication of John McCrae's war poem "In Flanders Fields," the poppy has been used to commemorate soldiers who have died in war.