Assessments of urban contexts using existing microclimate models mostly fall short, when considering topographies along with complex layouts of buildings and streets, regardless of their significant influences on building performances and outdoor environments. The challenge exists mainly due to modelâ??s inherent complexities and the associated high computational costs. This becomes especially ...

In this validation work two turbulence models (k-ε and SST model) and two grids (a finer hybrid grid and a tetrahedral coarser grid) are considered in order to model helium release and dispersion. Simulation results are compared against an experiment of jet release phenomena in the Battelle Model Containment facility (BMC), a multi-compartment facility with a total volume of about 560 m. In the...

FCC riser; Computational fluid dynamics (CFD); Cracking reaction kinetics; Hydrodynamics; 4-Lump kinetic model; k-Epsilon turbulence model Abstract Fluid catalytic cracking (FCC) is an essential process for the conversion of gas oil to gasoline. This study is an effort to model the phenomenon numerically using commercial computational fluid dynamics (CFD) software, heavy density catalyst and 4-...

in this paper, a cfd model of syngas flow in slurry bubble column was developed. the model is based on an eulerian-eulerian approach and includes three phases: slurry of solid particles suspended in paraffin oil and syngas bubbles. numerical calculations carried out for catalyst particles, bubble coalescence and breakup included bubble-fluid drag force and interfacial area effects. also, the ef...

Secondary settling tanks (SSTs) are the most hydraulically sensitive unit operations in biological wastewater treatment plants. The maximum permissible inflow to the plant depends on the efficiency of SSTs in separating and thickening the activated sludge. The flow conditions and solids distribution in SSTs can be predicted using computational fluid dynamics (CFD) tools. Despite extensive studi...

This paper describes a fully spectral, Polynomial Chaos method for the propagation of uncertainty in numerical simulations of compressible, turbulent flow, as well as a novel stochastic collocation algorithm for the same application. The stochastic collocation method is key to the efficient use of stochastic methods on problems with complex nonlinearities, such as those associated with the turb...

INTRODUCTION Computational fluid dynamics (CFD) has recently seen increased use in the design of pharmaceutical inhalers. The use of CFD in the design of inhalers is made difficult by the complex nature of aerosol generation. At present, CFD has provided valuable insight into certain aspects of inhaler performance, though limitations in computational power have prevented the full implementation...

a novel computational fluid dynamics and molecular kinetic theory (cfd-mk) method was developed to simulate the impingement of a nanodroplet onto a solid surface. a numerical solution of the navier–stokes equation using a volume-of-fluid (vof) technique was used to model nanodroplet deformation. dynamic contact angle during droplet impact was obtained by molecular kinetic theory. this dynamic c...

Intravascular stents are tubular structures placed into stenotic artery to expand the inside passage and improve blood flow. The mechanical factors affect the restenosis after stenting and image-based simulation has become a popular tool for acquiring information. The aim of this study was to demonstrate quantitatively and qualitatively the hemodynamic changes in coronary artery after stent imp...