11. 05. 2023 13:00

Mgr. Emil Varga, Ph.D. » Quasi-two-dimensional turbulent flows in superfluid helium

Department of Low Temperature Physics,

Mgr. Emil Varga, Ph.D.

Location: Seminar room KFKL, MFF UK (room F052 - ground floor near the rear staircase, Ke Karlovu 5)

Turbulent flows are chaotic and in three dimensions tend to destroy any order present in the flow. This behaviour changes drastically in two dimensions, where nonlinear processes lead to accumulation of energy at the largest scale through an inverse cascade, thus spontaneously ordering the flow into large-scale eddies. Superfluid helium is uniquely suited for the study of two-dimensional and quasi-two-dimensional turbulence, since the inviscid liquid easily flows into narrow channels and the interaction of quantized vorticity with thermal excitations (mutual friction) allows varying the dissipation suffered by the flow. Multiple types of critical phenomena in transition to turbulence are observed, with both flow velocity and temperature as control variables. The observed behaviour can be qualitatively explained through population dynamics of positive and negative discrete point vortices.
Seminar on Condensed Matter Theory

Group of Theoretical Physics organizes a regular seminar on theory of condensed matter physics.

Usually, we meet
every Thursdays at 13:00
in seminar room F 052
Ke Karlovu 5, 121 16 Praha 2.

You are welcome to join us!

If you wish to receive regular updates on fothcoming seminars, contact K. Carva.