Richardson’s Laws for Relative Dispersion in Colored-noise Flows with Kolmogorov-type Spectra

Invariance principle for inertial-scale behavior of scalar fields in Kolmogorov-type turbulence

We prove limit theorems for small-scale pair dispersion in synthetic velocity fields with power-law spatial spectra and wavenumber dependent correlation times. These limit theorems are related to a family of generalized Richardson’s laws with a limiting case corresponding to Richardson’s t3and 4/3-laws. We also characterize a regime of positive dissipation of passive scalars. © 2003 Elsevier Sc...

Richardson ' S Laws for Relative Dispersion in Colored - Noiseflows with Kolmogorov - Type Spectraalbert

Two-particle dispersion in model two-dimensional velocity fields

We consider two-particle dispersion in a velocity field, where the relative two-point velocity scales according to v(r) ∝ r and the corresponding correlation time scales as τ (r) ∝ r, and fix α = 2/3, as typical for turbulent flows. We show that two generic types of dispersion behavior arize: For α/2+β < 1 the correlations in relative velocities decouple and the diffusion approximation holds. I...

Modulation Response and Relative Intensity Noise Spectra in Quantum Cascade Lasers

Static properties, relatively intensity noise and intensity modulation response in quantum cascade lasers (QCLs) studied theoretically in this paper. The present rate equations model consists of three equations for the electrons density in the conduction band and one equation for photons density in cavity length. Two equations were derived to calculate the noise and modulation response. Calcula...

Particle dispersion processes in two-dimensional turbulence: a comparison with 2-D kinematic simulation

We study numerically the comparison between Lagrangian experiments on turbulent particle dispersion in 2-D turbulent flows performed, on the one hand, on the basis of direct numerical simulations (DNS) and, on the other hand, using kinematic simulations (KS). Eulerian space-time structure of both DNS and KS dynamics are not comparable, mostly due to the absence of strong coherent vortices and a...