Non-homogeneous, non-isotropic turbulence

Turbulent flows are often studied in two opposite conditions: in the presence of confining boundaries as in the case of pipe or channel flows, and with periodic boundary conditions with the aim to realize homogeneous-isotropic turbulence. Between these two cases there is a range of possibilities among which flows in which isotropy and/or homogeneity is broken by the large scale forcing (or flow) but still in the absence of physical boundaries.

This talk will report a series of numerical results in two classical examples of these flows: the turbulent Kolmogorov flow and the turbulent cellular flow produced by a BC forcing. The effects of inhomogeneity, anisotropy and non-stationarity on the small scale statistics of the turbulent flow will be discussed.