Data from turbulent numerical simulations of the global ocean demonstrate that the dissipation of kinetic energy obeys a nearly lognormal distribution at surprisingly large horizontal scales. As the horizontal scales of resolved turbulence are larger than the ocean is deep, the KolmogorovYaglom theory for intermittency in 3D homogeneous, isotropic turbulence cannot apply: instead the downscale ...

FSO communication systems links is vulnerable due to degrading effects of atmospheric turbulence and point errors. We investigate the error rate performance of Free-Space Optical (FSO) links over gamma-gamma turbulence fading channels in the presence of pointing error. Assuming Intensity-Modulation/Direct Detection (IM/DD) with On-Off Keying (OOK), a novel closed-form expression for BER of FSO ...

In this thesis I will examine the relations between turbulence as found in physical systems and turbulence in optic ow elds. I will record some image sequences of a theoretically well understood turbulent physical system and from these image sequences I will examine the relations between the optic ow of the image sequences and the physical parameters of the turbulent system. I will examine the ...

We report the observation of wave turbulence on the surface of a ferrofluid mechanically forced and submitted to a static normal magnetic field. We show that magnetic surface waves arise only above a critical field. The power spectrum of their amplitudes displays a frequency-power law leading to the observation of a magnetic wave turbulence regime which is experimentally shown to involve a 4-wa...

The direct numerical simulation (DNS) data of a turbulent, reacting boundary layer is used to study the turbulence-chemistry interaction and the scaling of the temperature fluctuations. We find that there is a feedback between the turbulence and the chemical reactions. Temperature fluctuations increase the reaction rates. Endothermic reactions reduce the magnitude of the temperature fluctuation...

This report presents an evaluation of the steady-state capability of the turbulence models available in the commercial CFD code FLUENT 6.0, for their application to the simulation of hydrofoil turbulent boundary layer separation at high-Reynolds numbers. Four widely applied two-equation RANS turbulence models were qualitatively and quantitatively assessed through comparison with high-quality ex...

Our recent work in which we study the propagation of the general Hermite-sinusoidal-Gaussian laser beams in wireless broadband access telecommunication systems is elaborated in this paper to cover the special case of an off-axis Gaussian beam. We mainly investigate the propagation characteristics in atmospheric turbulence of an off-axis Gaussian beam possessing Gaussian distributed random displ...

An experimental programme is presented, examining the turbulent wake of a monopile foundation in a current. Velocity was recorded across an extensive domain downstream of a model monopile in a 0.5 m deep basin, using an acoustic Doppler velocimeter array. The distribution of turbulent kinetic energy (TKE) is examined across the entire domain. Tests were undertaken using several combinations of ...

Expressions for the average intensity of both phase-locked and non-phase-locked Airy array beams propagating through atmospheric turbulence are derived based on the extended Huygens–Fresnel principle. The evolution of the average intensity distribution of both phase-locked and non-phase-locked Airy array beams during propagation in atmospheric turbulence is examined by numerical examples and is...