EXPERIMENTAL AND NUMERICAL INVESTIGATIONS OF LOW-TEMPERATURE SUPERFLUID TURBULENCE

Low-temperature superfluid turbulence is studied experimentally in a H elium swirling flow and numerically with the Gross-Pitaevskii equation in the geometry of the Taylor-Green (TG) vortex flow. Numerically, it was found in Nore er al. (1997a, b) that the kinetic energy transfer in the superfluid TG vortex is comparable to that of the viscous TG vo rtex and that the energy spectrum of the superflow is compatible with Kolmogrorov's scaling. The vorticity dynamics of the superflow are sim ilar to that of the viscous flow. In both cases, many vortex reconnect ion events happen throughout the how. Experimentally, power measuremen ts and pressure fluctuation spectra show very little difference above and far below the superfluid transition temperature, where the normal- fluid component of Helium is negligible (less than 5% in mass at T = 1 .2 K). (C) Elsevier, Paris.