![]() ![]() "It is remarkable that this point exists," Ahlers said. Vortices then occurred inside the flow and the warm fluid was transported faster from the bottom to the top than at lower rotation rates. ![]() But, at a certain critical rotation speed, the flow structure changed. When spinning the container slowly enough, no vortices occurred at first. Finally, the relation of the diameter of the cylinder to the height is also significant.Īhlers and his team discovered a new unexpected phenomenon that was not known before for turbulent flows like this. The temperature difference between the top and the bottom of the cylinder is another causal factor since it drives the flow in the first place. Rotation, such as the earth's rotation, is a key factor in the development of vortices. In addition, the whole cylinder was rotated around its own axis this had a strong influence on how the water flowed inside the cylinder. "Physicists like to take one ingredient of a complicated situation and study it in a quantitative way under ideal conditions." The research team, including first author Stephan Weiss, a postdoctoral fellow at UCSB, filled the laboratory cylinders with water, and heated the water from below and cooled it from above.ĭue to that temperature difference, the warm fluid at the bottom plate rose, while the cold fluid at the top sank a phenomenon known as convection. "To study the atmosphere would be too complicated for our purposes," said Guenter Ahlers, senior author and professor of physics at UCSB. The results are published in the journal Physical Review Letters. Using laboratory cylinders from 4 to 40 inches high, the team studied these underlying physical processes. These phenomena in earth's interior and its atmosphere are both governed by the same natural mechanisms, according to experimental physicists at UC Santa Barbara working with a computation team in the Netherlands. While in the atmosphere these vortices include cyclones and hurricanes, in the outer core they are essential for the formation of the earth's magnetic field. The earth's atmosphere and its molten outer core have one thing in common: Both contain powerful, swirling vortices. ![]()
0 Comments
Leave a Reply. |
Details
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |