Mysterious Turbulence
Whether it's hurricanes, the flow of blood in arteries or waterfalls: We are surrounded by turbulence. And yet researchers are still a long way from understanding the mysterious phenomenon. Now a new laboratory procedure could bring the breakthrough.
It's time to feed the blob. Foaming and voracious, it sucks up eight plate-sized portions every few seconds. What we refer to here as a blob is a stable turbulent blob in a giant tank of water in the lab of University of Chicago physicist William Irvine.
Unlike all turbulence observed so far, it is not a diffuse swirling flow that increases or decreases over time. Instead, the blob resembles a self-contained, bubbling sphere, unmoving the water around it. In order to create, and especially sustain, the unusual phenomenon, Irvine and his graduate student Takumi Matsuzawa must repeatedly blast it with eight ring-shaped vortices, the liquid equivalent of smoke rings. "This is how we build up the turbulence bit by bit," explains Matsuzawa.
Because the two researchers control the ring-shaped vortices very precisely, they can study the resulting turbulence at close range. The blob could thus provide glimpses into a chaotic world that physicists have been chasing for more than two centuries…
