Local investigation of superfluid turbulence

Abstract

We investigate flows of helium IV driven by two counter-rotating disks, in a range of temperatures varying between 1.4 and 2.3 K. The local pressure fluctuations obtained on a small total-head tube are analyzed. Above Tλ, the sensor allows to measure the local velocity fluctuations, and below Tλ, it determines the local fluctuations of a linear combination of the normal and superfluid flow components. Above and below Tλ, Kolmogorov spectra are clearly obtained, with similar Kolmogorov constants. Evidence for persistence of inertial range intermittency in the superfluid region is presented. At all temperatures below Tλ, the structure function exponents are found indistinguishable from those currently observed in normal fluid turbulence.