It is experimentally shown that the nonclassical high Reynolds number energy dissipation behavior, C(ε)≡εL/u(3)=f(Re(M))/Re(L), observed during the decay of fractal square grid-generated turbulence (where Re(M) is a global inlet Reynolds number and Re(L) is a local turbulence Reynolds number) is also manifested in decaying turbulence originating from various regular grids. For sufficiently high...

Fig. 1. Omnidirectional energy spectrum E(k) versus wavenumber k, computed from Eqs. (9)-(11), for the case A = 0:7, = 1, varying the rotation rate = 0; 10; 100. There is a smooth transition from the Komogorov`? 5=3' case = 0 to a spectrum = 100 that approaches a ` ? 2' form. Spontaneous breaking of reeexional symmetry in real quasi-two-dimensional turbulence: stochastic traveling waves and hel...

The mechanism by which the quantized vortex tangle in a turbulent superfluid system decays remains little understood [1]. Research into the subject suggests that Kelvin waves play an integral part in the dissipation process [2]. To generate quantum turbulence, a grid is dragged through 4 He which has condensed into the superfluid state. Oscillations in the motion of this grid remain a problem, ...

We report measurements of quantum turbulence generated by a vibrating grid in superfluid HeB at zero pressure in the zero temperature limit. Superfluid flow around individual vortex lines Andreev-reflects incoming thermal ballistic quasiparticle excitations, and allows non-invasive detection of quantum vortices in He-B. We have compared two Andreev reflection-based techniques traditionally used...

A grid of bars towed through a sample of He II produces both superfluid turbulence and classical hydrodynamic turbulence. The two velocity fields-in the normal fluid and in the superfluid-have been observed to have the same energy spectral density over a large range of scales. Here, we introduce a characteristic scale l(q)=2 pi(epsilon/kappa(3))(-1/4), where epsilon is the rate of turbulent ene...

We compare streamline statistics in stationary homogeneous isotropic turbulence and in turbulence generated by a fractal square grid. We examine streamline segments characterised by the velocity difference u D and the distance l between extremum points. We find close agreement between the stationary homogeneous isotropic turbulence and the decay region of the fractal-generated turbulence as wel...