Transition to Quantum Turbulence Generated by Thin Vibrating Wires in Superfluid 4He

Yano, H.; Ogawa, T.; Mori, Atsunobu; Miura, Y.; Nago, Yusuke; Obara, K.; Ishikawa, Osamu; Hata, Tōju

doi:10.1007/s10909-009-9888-9

Cited by 23 publications

(10 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…On reducing the drive, the velocity decreases towards the values measured in the potential flow state, but there remains a very small upward step in velocity corresponding to an abrupt transition back to the pure potential flow state. Similar behavior has been observed for vibrating wires [48,49] and vibrating spheres [50]. In the following, we use "down" sweeps taken with reducing drive so we can measure the turbulent drag to lower velocities.…”

Section: Turbulent Dragmentioning

confidence: 55%

See 1 more Smart Citation

Frequency-dependent drag from quantum turbulence produced by quartz tuning forks in superfluidHe4

et al. 2014

View full text Add to dashboard Cite

We have measured the drag force from quantum turbulence on a series of quartz tuning forks in superfluid helium. The tuning forks were custom made from a 75-μm-thick wafer. They have identical prong widths and prong spacings, but different lengths to give different resonant frequencies. We have used both the fundamental and overtone flexure modes to probe the turbulent drag over a broad range of frequencies f = ω/2π from 6.5 to 300 kHz. Optical measurements show that the velocity profiles of the flexure modes are well described by a cantilever beam model. The critical velocity for the onset of quantum turbulence at low temperatures is measured to be v c ≈ √ 0.7κ ω where κ is the circulation quantum. The drag from quantum turbulence shows a small frequency dependence when plotted against the scaled velocity v/v c .

show abstract

Section: Turbulent Dragmentioning

confidence: 55%

“…The onset of turbulence at low temperatures is known to be controlled by remanent vortices [48,49]. We might therefore expect that the critical velocity will also depend on the available pinning sites for remanent vortices, i.e., the surface roughness.…”

Section: Summary and Discussionmentioning

confidence: 99%

Frequency-dependent drag from quantum turbulence produced by quartz tuning forks in superfluidHe4

et al. 2014

View full text Add to dashboard Cite

show abstract

“…Here, we will describe briefly the essence of the observations by referring to a typical result from Yano et al [91]. A thin superconducting (typically NbTi) wire with a micron-size radius is formed into a semicircle, and its two edges are attached to the wall of a vessel.…”

Section: Quantum Turbulence Created By Vibrating Structuresmentioning

confidence: 99%

Quantized vortices in superfluid helium and atomic Bose– Einstein condensates

Tsubota¹,

Kasamatsu²,

Kobayashi³

2013

Novel Superfluids

View full text Add to dashboard Cite

“…These wires were the same as those used in previous studies. 15,20 They were made from a thin superconducting NbTi wire with a 3 m diameter fabricated from a commercial multifilament superconducting wire with dies. This fabrication technique produces wires with relatively smooth surfaces.…”

mentioning

confidence: 99%

“…After filling the cell with superfluid 4 He at a temperature below 100 mK over a period of 48 h, we found that there were bridge vortex lines attached to wire A near the pinhole but that wire B was effectively free of bridge vortices. 20 The above conditions are useful for studying turbulence transitions generated by a vibrating wire with no bridge vortices. 18,21 The responses of vibrating wire B, which was effectively free of vortices, are reproducible for both up and down sweeps of the driving force in a laminar-flow state ͑more precisely, a potential-flow state͒.…”

mentioning

confidence: 99%

Critical behavior of steady quantum turbulence generated by oscillating structures in superfluidH4e

et al. 2010

Self Cite

View full text Add to dashboard Cite

We report the critical behavior of steady quantum turbulence in superfluid 4 He. By using a thin vibrating wire with no bridge vortices in the superfluid, we find that lifetime of turbulent state for a given driving force reveals an exponential distribution. The mean lifetime estimated from the distribution decreases exponentially but greatly below a critical injection power. We estimate the vortex line density in the turbulent state and find that this critical behavior arises when the interdistance between vortex lines becomes as large as the turbulent region.Superfluid turbulence has attracted renewed experimental and theoretical interest as a result of recent investigations. 1 Turbulence in superfluid 4 He at very low temperatures consists only of a tangle of quantized vortex lines that defines superfluid flow. Hence, the energy flux in superfluid turbulence is described by the motions of the vortex lines. The energy of flows circulating vortex cores cascades from large vortex loops to smaller loops by reconnection ͑Richardson cascade͒; Kelvin waves with scales smaller than the vortex line spacing form along vortex lines and transfer energy from large wavelengths to smaller wavelengths ͑Kelvin wave cascade͒. 2-4 Consequently, the turbulence energy cascades from large scales to small scales, eventually dissipating at high wave numbers. This process can be observed in the decay of the density of vortex lines in superfluid helium 5,6 even at very low temperatures where the normal-fluid component is almost absent.Motions of vortex lines are also manifested in the continuous generation of turbulence by oscillating structures in superfluid 4 He. Experimental studies using oscillating spheres, 7 wires, 8,9 grids, 10 and tuning forks 11,12 indicate that superfluid turbulence can be generated at oscillating velocities above a critical velocity of about 50 mm/s. Vortex lines form bridges between a structure and its surrounding boundaries and they are shaken by the oscillation, developing into turbulence at velocities exceeding the critical velocity. 13,14 In a previous study, we found that a vibrating wire in the absence of bridge vortices also generates turbulence after vortex rings are applied from a vortex ring generator to the wire. 15 In a turbulent state, the vibrating wire continues to generate vortex lines even when further vortex rings are not applied. At sufficiently high driving forces, the generation seems to continue indefinitely. The wire velocity remains constant during the generation of vortex lines. However, the generation will stop suddenly when the driving force is reduced. After that, the vibrating wire cannot generate turbulence even at high velocities. This behavior is in marked contrast to the responses of other oscillating structures with bridge vortices, with respect to intermittent switching between turbulent flow and laminar flow or, more precisely, potential flow. 16,17 A vibrating wire with no bridge vortices determines the lifetime of the turbulent state in the turbulentto-laminar transitio...

show abstract

Transition to Quantum Turbulence Generated by Thin Vibrating Wires in Superfluid 4He

Cited by 23 publications

References 20 publications

Frequency-dependent drag from quantum turbulence produced by quartz tuning forks in superfluidHe4

Frequency-dependent drag from quantum turbulence produced by quartz tuning forks in superfluidHe4

Quantized vortices in superfluid helium and atomic Bose– Einstein condensates

Critical behavior of steady quantum turbulence generated by oscillating structures in superfluidH4e

Contact Info

Product

Resources

About