Quantum turbulence of bellows-drivenHe4superflow: 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...

Decay of capillary wave turbulence.

We report on the observation of freely decaying capillary wave turbulence on the surface of a fluid. The capillary wave turbulence spectrum decay is found to be self-similar in time with the same power law exponent as the one found in the stationary regime, in agreement with weak turbulence predictions. The amplitude of all Fourier modes are found to decrease exponentially with time at the same...