|COOKIES: By using this website you agree that we can place Google Analytics Cookies on your device for performance monitoring.|
Thermally and mechanically driven quantum turbulence in helium II
If you have a question about this talk, please contact Mustapha Amrani.
Topological Dynamics in the Physical and Biological Sciences
In most experiments with superfluid helium, turbulence is generated thermally (by applying a heat flux, as in thermal counterflow) or mechanically (by stirring the liquid). By modeling the superfluid vortex lines as reconnecting space curves with fixed circulation, and the driving normal fluid as a uniform flow (for thermal counterflow) and a synthetic turbulent flow (for mechanically driven turbulence), we determine the difference between thermally and mechanically driven quantum turbulence. We find that in mechanically driven turbulence, the energy is concentrated at the large scales, the spectrum obeys Kolmogorov scaling, vortex lines have large curvature, and the presence of coherent vortex structures induces vortex reconnections at small angles. On the contrary, in thermally driven turbulence, the energy is concentrated at the mesoscales, the curvature is smaller, the vorticity field is featureless, and reconnections occur at larger angles. Our results suggest a method t o experimentally detect the presence of superfluid vortex bundles.
This talk is part of the Isaac Newton Institute Seminar Series series.
This talk is included in these lists:
Note that ex-directory lists are not shown.
Other listsGurdon Institute Seminar Series Inner Space Talks Series Digitization of History Project: Centre for History and Economics, King's College
Other talksTBC "Flux controls flux - a fascinating way of control, with important consequences" TBC Lava, luck and linear logs Nanoparticle growth and Ostwald ripening: aggregate growth, size distributions, and the breakdown of scaling Running Out of Energy? The Future of the UK’s Electricity Supply.