Dissipation of Quasiclassical Turbulence in Superfluid 4He etc15 Tracking Number 166Presentation: Session: Superfluids 1 Room: Room E Session start: 10:30 Wed 26 Aug 2015 Andrei Golov golov@man.ac.uk Affifliation: The University of Manchester Dmitry Zmeev dzmeev@gmail.com Affifliation: Lancaster University Paul Walmsley Paul.Walmsley@manchester.ac.uk Affifliation: The University of Manchester Peter McClintock p.v.e.mcclintock@lancaster.ac.uk Affifliation: Lancaster University William Vinen w.f.vinen@bham.ac.uk Affifliation: University of Birmingham Topics: - Turbulence in superfluids Abstract: We compare the decay of turbulence in superfluid 4He produced by a moving grid to the decay of turbulence in the same channel created by either an impulsive spin-down to rest or by intensive ion injection. In all cases the vortex line density L at late time t decays as L ~ t^-3/2. Below 0.8 K, the spin-down turbulence maintains initial rotation and decays slower than grid turbulence and ion-jet turbulence. This is presumably due to the decoupling of the superfluid component from the normal one at large length scales at low temperatures, thus changing its effective boundary condition from no-slip to slip. |