Nano-shaped hot-wire for ultra-high resolution anemometry in cryogenic helium

Pantxo Diribarne (1) , Pierre Thibault (1) , Philippe-Emmanuel Roche (2)

1 SBT - Service des Basses Températures
2 NEEL - HELFA - Hélium : du fondamental aux applications

We present the principle, modelling, and the first implementation of a new type of high resolution hot-wire anemometer designed to operate at cryogenic temperatures and very high Reynolds numbers. Its spatial resolution of a few micrometers is comparable to the most spatially-resolved hot-wires reported in the literature. Compared to existing designs, its fabrication involves a limited number of steps, essentially the shaping at nanoscales of a superconducting NbTi wire of sub-micron diameter. The velocity spectra in the far wake of a centimeter-sized grid is measured as a proof of concept in stringent flow conditions.

Keywords: Hot Wire Anemometry; Turbulence; Cryogenie

Domains: Fluid mechanics [physics.class-ph]; Fluid Dynamics [physics.flu-dyn]

Pantxo Diribarne, Pierre Thibault, Philippe-Emmanuel Roche. Nano-shaped hot-wire for ultra-high resolution anemometry in cryogenic helium. Review of Scientific Instruments, 2019, 90 (10), pp.105004. ⟨10.1063/1.5116852⟩. ⟨cea-02282964v3⟩