in this paper, effects of the cross shore and groyne wall slopes on flow parameters around an impermeable groyne were considered using a three-dimensional numerical cfd model (i.e., fluent). the k-ε turbulence model was used to evaluate the reynolds stresses. the model was first applied to a vertical groyne on a flat bed and the model results were compared with the relevant experimental data. t...

Polarization properties of electromagnetic Gaussian Schell-model beams propagating through the anisotropic non-Kolmogorov turbulence of marine-atmosphere channel are studied based on the cross-spectral density matrix. Detailed analysis shows that the average polarization decreases with increasing the spectral index, inner scale of turbulence and generalized refractive-index structure parameter....

Transitional pipe flow is modeled as a one-dimensional excitable and bistable medium. Models are presented in two variables, turbulence intensity and mean shear, that evolve according to established properties of transitional turbulence. A continuous model captures the essence of the puff-slug transition as a change from excitability to bistability. A discrete model, which additionally incorpor...

To improve the calculation of the flow properties of an aerospike nozzle, different turbulence models were investigated in this study. The primary shape of the nozzle plug is determined through utilizing an approximate method. The flow field is, then, simulated using the Navier-Stokes equations for compressible flows. The commercial computational fluid dynamics code Fluent is used to simulate t...

The turbulent flow in a tangential inlet / tangential outlet vortex tube is numerically simulated using a modified   k turbulence model. The results are compared to experimental measurements from literature. The modified model shows better agreement with the local tangential velocity measurements compared to the standard and RNG   k turbulence models. The flow structure is also demonstrated...

The aim of our study is to analyze the impact of insertion holes in the middle of obstacles on the flow around a surface-mounted cube, In order to do this; we studied four configurations of obstacles in a channel with a Reynods number based on obstacle height ReH = 40000. The hexahedral structured meshes were used to solve the fluid dynamics equations .The finite volume method are employed to s...

A new subgrid eddy-viscosity model is proposed in this paper. Full details of the derivation of the model are given with the assumption of homogeneous turbulence. The formulation of the model is based on the dynamic equation of the structure function of resolved scale turbulence. By means of the local volume average, the effect of the anisotropy is taken into account in the generalized Kolmogor...

Different variants for buoyancy-affected terms in k-ε turbulence model have been utilized to predict the flow parameters more accurately, and investigate applicability of alternative k-ε turbulence buoyant closures in numerical simulation of a horizontal gravity current. The additional non-isotropic turbulent stress due to buoyancy has been considered in production term, based on Algebraic Stre...