The streamwise turbulence intensity in the intermediate layer of high Reynolds turbulent pipe flow

A modification of the Townsend-Perry attached eddy model is derived in order to reproduce a more realistic variation of the integral length scale. A new wavenumber range is introduced to the model at wavenumbers smaller than the Townsend-Perry k^(-1) spectrum. This necessary addition can also account for the high Reynolds number outer peak of...

Turbulent wakes of plates with non-equilibrium similarity scalings

We have conducted hot wire anemometry measurements of six different axisymmetric turbulent wakes which demonstrate the existence in all these wakes of non-equilibrium mean flow profile scalings and of the underlying self-preservation and non-equilibrium dissipation scalings. These mean flow profile scalings are different from those of all...

Energy dissipation and flux laws for unsteady turbulence

Direct Numerical Simulations of spatially periodic unsteady turbulence show that the high Reynolds number scalings of the instantaneous energy dissipation rate and interscale energy flux at intermediate wavenumbers are qualitatively different from the well-known $u'(t)^{3}/L(t)$ cornerstone scalings of equilibrium turbulence where $u'(t)$ and $L...

The spatial origin of -5/3 spectra in grid-generated turbulence

A combined wind tunnel and computational study of grid-generated turbulence along the centreline shows that the close to -5/3 power law signature of energy spectra in the frequency domain originates in the production region close to the grid where the velocity derivative statistics become quite suddenly isotropic but also where the turbulent...