Quantum turbulence decay

Quantum Turbulence Decay

We develop a computational model of quantum turbulence decay employing a kinematic prescription for the normal fluid. We find that after an initial transient, the length of the vortex tangle L decreases and for large times obeys the scaling law L ≈ t−0.45. The average magnitude (along the quantized vortices) of the superfluid and line-vortex velocity are close and differ significantly from the ...

Decay of homogeneous two-dimensional quantum turbulence

Decay of Quantized Vortices in Quantum Turbulence

The decay of quantized vortex line length in quantum turbulence at zero temperature is studied numerically by solving the Gross-Pitaevskii equation with a small-scale dissipation. The obtained decay of the vortex line length L is consistent with the L ∝ t −3/2 behavior which supports the Kolmogorov energy spectrum of quantum turbulence. The mechanism of the decay is discussed.

Decay of scalar turbulence revisited.

We demonstrate that at long times the rate of passive scalar decay in a turbulent, or simply chaotic, flow is dominated by regions where mixing is less efficient. We examine two situations. The first is of a spatially homogeneous stationary turbulent flow with both viscous and inertial scales present. It is shown that at large times scalar fluctuations decay algebraically in time at all spatial...

Wave Decay in Mhd Turbulence

We present a model for nonlinear decay of the weak wave in three-dimensional incompressible magnetohydrodynamic (MHD) turbulence. We show that the decay rate is different for parallel and perpendicular waves. We provide a general formula for arbitrarily directed waves and discuss particular limiting cases known in the literature. We test our predictions with direct numerical simulations of wave...