Physicists have uncovered a novel aspect of turbulent convection, showing it can cause a freely moving solid within a fluid to rotate in both clockwise and counterclockwise directions, with the possibility of switching between the two due to turbulence. This research, published in the Proceedings of the National Academy of Sciences, enhances our understanding of fluid dynamics in various contexts, from Earth’s molten core to boiling water. Conducted by Jun Zhang and Kaizhe Wang at NYU, the study focused on Rayleigh–Bénard convection, wherein fluid movement is induced by heating from below.
In their experiments involving a cylindrical container filled with water heated from the bottom, the team observed smooth rotational behavior in the turbulent flows as they interacted with a suspended rectangular panel. Their findings indicated that the solid can rotate in correlation with the turbulent flows, with direction and rotational speed affected by the convection intensity. Remarkably, they demonstrated that turbulence can be controlled through interactions with solid objects. This discovery not only emphasizes the complexity of turbulent systems but also suggests that thermal convection may hold significant implications for geological processes within Earth.
