[1] Modeling turbulent flows at high Reynolds number requires solving simplified variants of the Navier-Stokes equations. The methods used to close the resulting Reynolds-averaged, or eddy simulation equations usually follow classical theory and, at small enough scales, postulate universal scaling for turbulence that is independent of the velocity itself. This may not be the best way to concept...

{ Rotating uid systems can display large scale asymmetries about the equator. A model-independent mechanism for such symmetry-breaking is described, via a spiralling intermittency that combines the on-oo and Pomeau-Manneville mechanisms. This involves a periodic orbit in an invariant subspace becoming unstable to perturbations transverse to the subspace, these are describable in terms of the eq...

Suppose a smooth dynamical system has an invariant subspace and a parameter that leaves the dynamics in the invariant subspace invariant while changing the normal dynamics. Then we say the parameter is a normal parameter, and much is understood of how attractors can change with normal parameters. Unfortunately, normal parameters do not arise very often in practise. We consider the behaviour of ...

We measure the pressure difference during two-phase flow across a sandstone sample for range of injection rates and fractional flows water, wetting phase, an imbibition experiment. quantify onset transition from linear relationship between rate gradient to nonlinear power-law dependence. show that (Darcy) exponent in is function flow. use energy balance accurately predict intermittency flows, f...

We present a new method of fractal-based texture analysis, using the multiscale fractional Brownian motion texture model, and a new parameter, intermittency. The intermittency parameter p describes a degree of presence of the textural information: a low value of p implies a very lacunar texture. The multi-scale fractional Brownian motion model allows to construct multiregime textures in the fre...

In order to describe the phenomenon of intermittency in wall turbulence and, more particularly, the behaviour of moments p r V δ and p r ε and intermittency exponents ζP with the order p and distance to the wall, we developed a new geometrical framework called “entropic-skins geometry” based on the notion of scale-entropy which is here applied to an experimental database of boundary layer flows...

Ever since Kolmogorov’ introduced the intermittency exponent, more than a dozen attempts have been made to obtain its numerical value from experiments. The resulting estimates have varied from as low a value as 0.18 to as high as 0.7. (See Ref. 2 for a summary of early measurements, Table IV of Ref. 3 for measurements until about 1975 and Refs. 4-10 for experiments made thereafter.) It is unsat...

The light-induced spectral diffusion and fluorescence intermittency (blinking) of semiconductor nanocrystal quantum dots are investigated theoretically using a diffusion-controlled electron-transfer (DCET) model, where a light-induced one-dimensional diffusion process in energy space is considered. Unlike the conventional electron-transfer reactions with simple exponential kinetics, the model n...

In characterizing fully developed turbulence by means of statistical methods, it is still an actual problem to explain what happens if one transits from large scales (scale of the system) to small scales (dissipationrange scale or Kolmogorov microscale). From experiments it is known that the shape of the probability density functions (PDF) of velocity differences between two points dur = (y(y +...

Civil and Environmental Engineering) Intermittency and Irreversibility in the Soil-Plant-Atmosphere System