Until recently, physical models were the only way to investigate into the details of breakwaters behavior under wave attack. From the numerical point of view, the complexity of the fluid dynamic processes involved has so far hindered the direct application of Navier-Stokes equations within the armour blocks, due to the complex geometry and the presence of strongly non stationary flows, free bou...

In this study, turbulent compressible gas flow in a rectangular micro-channel is numerically investigated. The gas flow assumed to be in the subsonic regime up to Mach number about 0.7. Five low and high Reynolds number RANS turbulence models are used for modeling the turbulent flow. Two types of mesh are generated depending on the employed turbulence model. The computations are performed for R...

A heated room is numerically analyzed to study thermal comfort. Cold air flowing in from the inlet gets by a heat source (placed just below inlet), before being distributed throughout room. The presence of and high Rayleigh number causes flow be buoyant turbulent. Two RANS based turbulence models, RNG k-ε k-ω SST models are used model Discrete Ordinate (DO) radiation transfer between different ...

The separation process of oily water using membranes has attracted the attention researchers and engineers. greater problem in use membrane is reduction permeate flux due to clogged pores by oil deposition inside or effect concentration polarization. For this purpose, a theoretical study water/oil module was performed. This device consists tubular ceramic provided with rectangular inlet section...

In single-bend channels or meandering channels, groynes are widely used as a river-training structure. Geometric factor is an important principle of groyne design. this paper, the numerical method based on Renormalization Group (RNG) k-ε turbulence model to study effects with different lengths and orientations mean flow pattern characteristics in mildly channel. The analysis shows that compared...

Background Renewable Natural Gas (RNG) is pipeline quality gas that is fully interchangeable with fossil natural gas but is produced from a renewable feedstock and can be used as a 100% substitute for, or blended with, conventional natural gas streams [1]. RNG is an important alternative fuel that can help the State of California meet several GHG and renewable energy targets. As a transportatio...

Two-dimensional numerical analysis is conducted to determine the influence of upstream surface modifications a novel clerestory shaped rib turbulator on thermal performance augmentation. The divided into two parts where upper always normal incoming flow and lower surface, which inclined flow. elevation vertical varied using non-dimensional approach length (h/e=0, 0.25, 0.5 0.75), inclination an...

This paper and its companion (Part I) are devoted to to the analysis of the application of a chaotic piecewise-linear one-dimensional (PL1D) map as Random Number Generator (RNG). In Part I, we have mathematically analyzed the information generation process of a class of PL1D maps. In this paper, we find optimum parameters that give an RNG with lowest redundancy and maximum margin against parasi...

This study aims to explain and elaborate a new model for the business environmental hostility in small and medium enterprises in the science and technology park in Kermanshah (Iran). The research method is a mixed method. Content analysis was used in the qualitative part, and a confirmatory factor analysis was used in the quantitative section. In the qualitative section for the environmental ho...

A non-premixed coaxial oxy-fuel turbulent flame was studied numerically with standard and realizable k-ε turbulence model and a comparison was made between them. The governing equations were solved by finite volume approach and were discretized using the second order upwind scheme. The presumed β-PDF model was applied to model turbulence-combustion interaction. The discrete ordinate radiation h...