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Turbulent flow around an oscillating body in superfluid helium: dissipation characteristics of the nonlinear regime
(Springer, 2013-01)
By examining the resonance curves of an oscillator submerged in superfluid liquid helium, it is found that their shape is affected by two distinct dissipation regimes when the amplitude is large enough to generate turbulence ...
Anomalous Trajectories of H2 Solid Particles Observed Near a Sphere Oscillating in Superfluid Turbulent 4He
(Springer, 2013-05)
Using a relatively low cost apparatus, consisting of a glass dewar and a digital camera capable of taking images at 240 frames per second we have observed trajectories of frozen H2 particles which follow the flow of liquid ...
Dual cascade and dissipation mechanisms in helical quantum turbulence
(American Physical Society, 2017-05)
While in classical turbulence helicity depletes nonlinearity and can alter the evolution of turbulent flows, in quantum turbulence its role is not fully understood. We present numerical simulations of the free decay of a ...
Two-dimensional supersonic nonlinear Schrodinger flow past an extended obstacle
(AMER PHYSICAL SOC, 2009)
Supersonic flow of a superfluid past a slender impenetrable macroscopic obstacle is studied in the framework of the two-dimensional (2D) defocusing nonlinear Schroumldinger (NLS) equation. This problem is of fundamental ...
Extended fluid-dynamics and collective motion of two trapped fermion species with pairing interactions
(Springer/Plenum Publishers, 2011-02)
We extend our earlier fluid-dynamical description of fermion superfluids incorporating the particle energy flow together with the equation of motion for the internal kinetic energy of the pairs. The formal scheme combines ...
Analysis of motion of solid hydrogen tracer particles in oscillating superfluid flows
(Institute of Physics Publishing, 2014-10)
We have developed a relatively simple cryostat which allows us to image turbulent flows in superfluid helium at temperatures below 2 K, using frozen H2 particles. We analyze the statistics of the velocities of these solid ...
Spatiotemporal detection of Kelvin waves in quantum turbulence simulations
(American Physical Society, 2015-12)
We present evidence of Kelvin excitations in space-time resolved spectra of numerical simulations of quantum turbulence. Kelvin waves are transverse and circularly polarized waves that propagate along quantized vortices, ...
Abrupt Transition between Three-Dimensional and Two-Dimensional Quantum Turbulence
(American Physical Society, 2020-04)
We present numerical evidence of a critical-like transition in an out-of-equilibrium mean-field description of a quantum system. By numerically solving the Gross-Pitaevskii equation we show that quantum turbulence displays ...
Mutual friction in helium II: A microscopic approach
(American Institute of Physics, 2009-12)
We develop a microscopic model of mutual friction represented by the dissipative dynamics of a normal fluid flow which interacts with the helical normal modes of vortices comprising a lattice in thermal equilibrium. Such ...