Regensburg 2013 – scientific programme
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DY: Fachverband Dynamik und Statistische Physik
DY 27: Fluid Dynamics and Turbulence
DY 27.3: Talk
Thursday, March 14, 2013, 10:00–10:15, H48
Dynamical scaling of the critical velocity for the onset of turbulence in oscillatory superflows — •Wilfried Schoepe1 and Risto Hänninen2 — 1Universität Regensburg — 2Aalto University Helsinki
The critical velocity for the onset of turbulence in oscillatory superflows vc is universal and scales as √κ ω, where κ is the circulation quantum of the superfluid vortices and ω is the oscillation frequency. This behavior was observed experimentally and can be derived theoretically in various ways, e.g., from dimensional considerations, from the superfluid Reynolds number Rs = (v l)/κ (where v is the flow velocity and l is a characteristic length scale), and rigorously by means of dynamical scaling of the equations of motion of vortex dynamics.