to enhance the understanding of the impact of obstacle buildings on pollution transportationand dispersion in the atmospheric boundary layer, it is necessary to know the atmospheric flow characteristics over terrains. wind flow characteristics in a boundary layer over a step-shaped cliff topography model with rough and smooth surfaces were studied numerically using computational fluid dynamics ...

the design and optimization of hydrocyclones using cfd techniques are gaining popularity and the key to a successful simulation lies with the accurate description of the high turbulent swirling behavior of the flow. this paper presents a detailed comparison between the omega rsm and the rng k–e turbulence model, which are both derived specially for modeling swirling or rotational flow, in the s...

Abstract The accuracy of wind flow simulation in mountain area micro-topography is related to discrete scheme, turbulence model and wall function. In this paper, the standard hill adopt analyze calculation different models. Four models, including RNG k-ε, k-ω , SST TSST were used calculation, compared with result tunnel test. results second-order upwind or scalable function are basically consis...

A quad inserted into a turbulent boundary layer of a flat plate and its effect on average heat transfer and the friction coefficient is studied. To optimize this effect, the edge sizes and distance of the quad from the flat plate are continually modified. In each case, simultaneously the heat transfer enhancement and reduction in skin friction are analyzed. For optimization, the genetic algorit...

Abstract This paper establishes the computational fluid dynamics models of marine submersible buoy system. The use incompressible Navier-Stokes equations, Renormalization-Group (RNG) turbulence model and fractional areas/volume obstacle representation method. Using lumped mass mothed to simulate anchor line power supply cable. result show that great tension forces increase occurs at moment when...

in this paper, by numerical simulation of gas flow, effects of divergence angles on the amplification factor, side force and thrust vector magnitude of a moveable nozzle with supersonic split line have been investigated. the study is conducted for constant exit to throat area ratio and the location of the split line is also constant. the finite volume method with second order upwind scheme for ...

The turbulent pulsatile blood flow through stenosed arteries considering the elastic property of the wall is investigated numerically. During the numerical model validation both standard k-ε model and RNG K-ε model are used. Compared with the RNG K-ε model, the standard K-ε model shows better agreement with previous experimental results and is better able to show the reverse flow region. Also, ...

The Fuzzy C-means (FCM) method with Fourier coefficient based distance was firstly used to construct the vortex features and analyze large-scale unsteady flow pattern around building by transient ensemble velocity magnitude Q criterion value. performance of Reynolds-averaged Navier-Stokes (URANS) turbulence models, including Standardk−εmodel, Realizablek−ε, Renormalization Group (RNG) theoryk−ε...

Using computational fluid dynamics (CFD) techniques to model buoyancy-driven airflows has always proved challenging. This work investigates CFD modelling of buoyancy-driven natural ventilation flows in a single-storey space connected to an atrium. The atrium is taller than the ventilated space and when warmed by internal heat gains producing a column of warm air in the atrium and connect space ...