82 citations · 480 across the 19 of their papers we have counts for
10 papers · 1 filter
Breakdown of Potential Flow to Turbulence around a Sphere Oscillating in Superfluid He-4 above the Critical Velocity
W. Schoepe, R. Hänninen, M. Niemetz
The onset of turbulent flow around an oscillating sphere in superfluid He is known to occur at a critical velocity where is the circulation quantum and…
Quantum turbulence in superfluids with wall-clamped normal component
Vladimir Eltsov, Risto Hänninen, Matti Krusius
In Fermi superfluids, like superfluid 3He, the viscous normal component can be considered to be stationary with respect to the container. The normal component interacts with the su…
Comment on "Motion of a helical vortex filament in superfluid 4He under the extrinsic form of the local induction approximation"
Niklas Hietala, Risto Hänninen
We comment on the paper by Van Gorder ["Motion of a helical vortex filament in superfluid He under the extrinsic form of the local induction approximation", Phys. Fluids 25,…
Vortex filament method as a tool for computational visualization of quantum turbulence
Risto Hänninen, Andrew W. Baggaley
Vortex filament model has become a standard and powerful tool to visualize the motion of quantized vortices in helium superfluids. In this article, we present an overview of the me…
Identification of Kelvin waves: numerical challenges
R. Hänninen, N. Hietala
Kelvin waves are expected to play an essential role in the energy dissipation for quantized vortices. However, the identification of these helical distortions is not straightforwar…
Turbulent Vortex Flow Responses at the AB Interface in Rotating Superfluid 3He-B
P. M. Walmsley, V. B. Eltsov, P. J. Heikkinen +3
In a rotating two-phase sample of 3He-B and magnetic-field stabilized 3He-A the large difference in mutual friction dissipation at 0.20 Tc gives rise to unusual vortex flow respons…
Asymptotic motion of a single vortex in a rotating cylinder
J. M. Karimäki, R. Hänninen, E. V. Thuneberg
We study numerically the behavior of a single quantized vortex in a rotating cylinder. We study in particular the spiraling motion of a vortex in a cylinder that is parallel to the…
Super Stability of Laminar Vortex Flow in Superfluid 3He-B
V. B. Eltsov, R. de Graaf, P. J. Heikkinen +4
Vortex flow remains laminar up to large Reynolds numbers (Re~1000) in a cylinder filled with 3He-B. This is inferred from NMR measurements and numerical vortex filament calculation…
Universal onset of quantum turbulence in oscillating flows and crossover to steady flows
R. Hänninen, W. Schoepe
The critical velocity v_c for the onset of quantum turbulence in oscillatory flows of superfluid helium is universal and scales as v_c \sim \sqrt{κω}, where κis the circulation qua…
Turbulent dynamics in rotating helium superfluids
V. B. Eltsov, R. de Graaf, R. Hanninen +5
New techniques, both for generating and detecting turbulence in the helium superfluids 3He-B and 4He, have recently given insight in how turbulence is started, what the dissipation…