|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 listsDPMMS info aggregator History and Economics Seminar The Shrinking Commons Symposium: Plenary Lectures
Other talksModelling the growth of laccoliths: Static and dynamic fluid-driven fracturing of adhered elastica Production Processes Group Seminar - "Leonardo da Vinci's studies of friction." Hadean, pre-biotic Photosynthesis and Enzyme-like Heterogeneous Catalysts: Mimicking a state we do not know Uncovering the Glass Cliff: Women's leadership roles in times of crisis TBA Unorthodox Interactions at Work