Decay of Homogeneous Turbulence from a Given Initial State

Decay of homogeneous two-dimensional quantum turbulence

Decay of magnetohydrodynamic turbulence from power-law initial conditions.

We derive relations for the decay of the kinetic and magnetic energies and the growth of the Taylor and integral scales in unforced, incompressible, homogeneous, and isotropic three-dimensional magnetohydrodynamic (3DMHD) turbulence with power-law initial energy spectra. We also derive bounds for the decay of the cross and magnetic helicities. We then present results from systematic numerical s...

3D Homogeneous Turbulence

In this chapter we focus on what can be called the purest turbulence problem, as well as the classical one. It is in fact so pure that, strictly speaking, it cannot exist in nature, although experience shows that natural turbulence often has behavior remarkably close to the pure form. This is the case where rotational and gravitational forces are negligible (i.e., g = f = 0); b or c can be cons...

2D Homogeneous Turbulence

2D homogeneous turbulence is relevant to geophysical turbulence on large horizontal scales because of the thinness of Earth’s atmosphere and ocean (i.e., H/L 1) and Earth’s rotation (i.e., Ro 1) and stable stratification (i.e., Fr 1), both of which tend to suppress vertical flow and make the 2D horizontal velocity component dominant. A detailed explanation for this involves the theory for geost...

The multiscale formulation of large eddy simulation: Decay of homogeneous isotropic turbulence

The variational multiscale method is applied to the large eddy simulation ~LES! of homogeneous, isotropic flows and compared with the classical Smagorinsky model, the dynamic Smagorinsky model, and direct numerical simulation ~DNS! data. Overall, the multiscale method is in better agreement with the DNS data than both the Smagorinsky model and the dynamic Smagorinsky model. The results are some...