Search on MyScienceWork's publications

Object of this work were the steady state and the transient properties of a tangle of quantized vortex lines - the so-called superfluid turbulence - in a counterflow The experiments were performed in the temperature range from 1 5 to 2 0 K using a wide counterflow channel 3 16 x 0 95 cm 2 cross sectional area 20 cm length and heat fluxes in the order of 0 1 W cm 2 The vortex line density a characteristic value for the superfluid turbulence was determined by two different methods 1 from measuring the temperature difference along the main flow direction and 2 from the damping of axial and longitudinal second sound resonances determined with a superconducting gold-tin-bolometer In the steady state range the mean vortex line density and by using the above mentioned two independent measuring procedures also the homogeneity and the isotropy of the vortex tangle could be determined The main results confirmed existing experimental data The measurements for the transient behavior concerned mainly the so-called anormalous slow decay and for the first time were performed systematicely in a wide range of parameters From the obtained results a new model could be developed taking into account the interaction between the normal and the superfluid turbulence For this purpose the characteristic length scales of both the normal and the superfluid turbulence were compared It turned out that the change to the slow decay state was accompanied by a change in the dominant friction forces i e a transition from a regime governed by the mutual friction to a regime controlled by viscous dissipation In addition also other modells and the possible influence of the spatial structure of the vortex tangle on the slow decay process were discussed orig SIGLE Available from TIB Hannover RA 1396 1994 9 FIZ - Fachinformationszzentrum Karlsruhe TIB - Technische Informationsbibliothek DE Germany

Eine experimentelle Untersuchung zu Waermetransport und Wirbeldynamik in superfluidem Helium

An experimental investigation on heat transport and vortex dynamics in superfluid helium / Eine experimentelle Untersuch...

Publication search with SECOND SOUND as keyword

Eine experimentelle Untersuchung zu Waermetransport und Wirbeldynamik in superfluidem Helium

An experimental investigation on heat transport and vortex dynamics in superfluid helium / Eine experimentelle Untersuch...

Publication search
with SECOND SOUND as keyword