Appropriate descriptions of turbulence are important in predicting sediment transport and seabed evolution. We use here a three-dimensional model to investigate the impacts of sediment-induced stratification, erosion parameterization, and turbulence closures on sediment transport and morphological simulations. The model is implemented in the Proudman Oceanographic Laboratory Coastal Ocean Model...

A statistical mechanics model of isotropic turbulence that renormalizes the effects of turbulent stresses into a velocity-gradient-dependent random force term is introduced. The model is well-defined within the context of the renormalization group expansion, as the effective expansion parameter is O( ). The Kolmogorov constant and N parameter of turbulence are of order unity, in accord with exp...

Turbulent flow over an array of wall-mounted cubic obstacles has been numerically investigated using large-eddy simulation. The simulations have been performed using high-performance computations with local cluster systems. The array of cubes are fully submerged in a simulated deep rough-wall atmospheric boundary-layer with high turbulence intensity characteristics of environmental turbulent fl...

Shell models of turbulence have been employed as toy models which, in their chaotic states, show statistical properties similar to real fluid turbulence, including Kolmogorov energy spectrum and intermittency. These models are interesting because, at the present stage, it is still quite difficult or almost impossible to study relations between those traditional statistical properties and the st...

Analytical formulas are derived for the average intensity, the root-mean-square (rms) angular width, and the M2-factor of Laguerre-Gaussian correlated Schell-model (LGCSM) beam propagating in non-Kolmogorov turbulence. The influence of the beam and turbulence parameters on the LGCSM beam is numerically calculated. It is shown that the quality of the LGCSM beam can be improved by choo...

The knowledge of the characteristics of the atmospheric turbulence is of fundamental importance in order to improve the performances of the adaptive optics systems in the next generation of telescopes. Starting from the statistical description of the turbulence, we derive a random field spatial model of the turbulent phase. Then we use this spatial statistical model to compute the spatial innov...

of turbulence models for shear ows by a double expansion technique," Phys. Fluids \Conservation laws and two ux spectra of hydro-dynamic convective turbulence," Physica D 57 (1992). 15 Bolgiano and Kolmogorov scaling are believed to occur together in general ows; this suggests that the general dissipation rate model could combine the results for both scalings as in Eq. (40). 2 However, a comple...

Almost all computational fluid dynamics (CFD) simulations of flow around marine propellers use turbulence models that are only well suited for fully turbulent flows, which in some cases may lead to accuracy degradation in the prediction of propeller performance characteristics. The discrepancy between computed thrust and torque and corresponding experimental data increases with increasing prope...

The Lagrangian view of passive scalar turbulence has recently produced interesting results and interpretations. Innovations in theory, experiments, simulations and data analysis of Lagrangian turbulence are reviewed here in brief. Part of the review is closely related to the so-called Kraichnan model for the advection of the passive scalar in synthetic turbulence. Possible implications for a be...