Generation of turbulence by vibrating forks and other structures in superfluidH4e

Applications of the quartz tuning fork in classical and superfluid hydrodynamics

“…3 The drag coefficient as a function of prong velocity for various temperatures in superfluid helium. The measured data is again marked by open circles, while the solid lines correspond to fitting functions described thoroughly in [30], where a detailed analysis of the observations can be found as well. It is shown that the character of the observed transition to turbulence is very different for a classical fluid (data taken at 4.2 K at 15 bar) and for superfluid helium with only about 3% of the normal component (data taken at 1.32 K), where a local maximum of the drag coefficient is observed before it levels off at a value of about 1 corresponding to developed turbulence.…”

“…For the observed values of the critical velocity and the effective kinematic viscosity, please refer to [30].…”

“…Viscous drag is no longer the dominant drag force, but it still functions as the eventual mechanism of energy dissipation in the normal component. An empirical mathematical model describing the two components with a varying degree of coupling has been put forward and compared with the experimental data in [30].…”

Turbulent cascade of Kelvin waves on vortex filaments

“…Turbulence can be created in superfluid helium by agitating it using propellers [1], grids [2], forks [3] or wires [4], by applying a heat flow [5] or by injecting a stream of ions [6]. Superfluid turbulence is particularly simple if the temperature is reduced to less than 1 K because thermal excitations become negligible and liquid helium can be considered a pure superfluid.…”

A Quasiparticle Detector for Imaging Quantum Turbulence in Superfluid $$^3$$ 3 He-B

“…Quartz tuning forks have very high quality factors, of order 10 5 , making them sufficiently sensitive to study the mechanical properties of helium fluids at low temperatures. They have found many applications in superfluids research including measurements of viscosity [5][6][7], quantum turbulence in 4 He [8][9][10], cavitation [11], Andreev scattering in 3 He-B [12,13] and acoustic modes [14][15][16]. Here we describe their use as sensitive probes of ballistic quasiparticles in superfluid 3 He-B.…”