Turbulent flow around an oscillating body in superfluid helium: dissipation characteristics of the nonlinear regime
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 in the liquid. In a resonance curve, the central part close to resonance, m...
| Authors: | ; |
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| Format: | Article |
| Status: | Published version |
| Publication date: | 2013 |
| Country: | Argentina |
| Institution: | Consejo Nacional de Investigaciones Científicas y Técnicas |
| Repository: | CONICET Digital (CONICET) |
| Language: | English |
| OAI Identifier: | oai:ri.conicet.gov.ar:11336/26669 |
| Online Access: | http://hdl.handle.net/11336/26669 |
| Access Level: | Open access |
| Keyword: | Quantum Fluids Turbulence Superfluid Helium Nonlinear Oscillator https://purl.org/becyt/ford/1.3 https://purl.org/becyt/ford/1 |
| Summary: | 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 in the liquid. In a resonance curve, the central part close to resonance, may be in a turbulent regime, but the response is of much lower amplitude away from the resonance frequency, so that the oscillation can still be in the linear regime for frequencies not exactly at resonance. This introduces an ambiguity in estimating the inverse quality factor Q − 1 of the oscillator. By analyzing experimental data we consider a way of matching the two ways of estimating Q − 1 and use the information to evaluate the frictional force as a function of velocity in a silicon paddle oscillator generating turbulence in the superfluid. |
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