Computational Fluid Dynamics is now a new ramification of the numerical discretization method based on high-performance electronic computers, which focuses on fluid mechanics simulation. Fluid mechanics has two main braches that one is theoretical analysis and another is experimental research. Therefore, theoretical and experimental fluid mechanics were created as most important constituents in...

Gas-phase velocity fluctuations in fixed particle beds and freely evolving suspensions are quantified using particle-resolved direct numerical simulation (PR-DNS). The flow regime corresponds to homogeneous gas-solid systems typically encountered in fluidized bed risers, with high solid to gas density ratio and particle diameter being greater than the dissipative length scales. The contribution...

this study is concerned with the prediction of particles’ velocity in a dilute turbulent gas-solidboundary layer flow using a fully eulerian two-fluid model. the closures required for equationsdescribing the particulate phase are derived from the kinetic theory of granular flows. gas phaseturbulence is modeled by one-equation model and solid phase turbulence by mlh theory. resultsof one-way and...

Flotation process in mechanical cells is carried out in highly turbulent conditions. In this work, the impact of impeller speed on four characteristics of the quiescent zone, i.e. zone height, turbulence, solid percentage, and gas holdup, and their relationship with the entrainment is investigated, and it is shown why at a higher impeller speed, entrainment is not significant. The height of the...

Tile problem of planctary system formation and its subsequent character can only be addressed by studying the global evolution of solid material entrained in gaseous protoplanetary disks. We start to investigate this problem by considering the space-time development of aerodynamic forces that cause solid particles to dccouple from the gas. The aim of this work is to demonstrate that only the sm...

A unique normalized radial pressure profile characterizes the bed of a gas-solid vortex reactor over a range of particle densities and sizes, solid capacities, and gas flow rates: 950-1240 kg/m3, 1-2 mm, 2 kg to maximum solids capacity, and 0.4-0.8 Nm3/s (corresponding to gas injection velocities of 55-110 m/s), respectively. The combined momentum conservation equations of both gas and solid ph...

in this research, a cold model of internally circulating fluidized bed is investigated. the aim is to find the effects of some of the operating parameters on the performance of the reactor. experiments were carried out in a glass column (30 mm i.d. and 25 cm height) with a centrally located draft tube (11 mm i.d. and 5 or 7 cm height). the bed was loaded with white silica particles (dp = 0.15 -...

Experimental observations revealed that the stagnant zone, which forms in the lower central part of a blast furnace, is an important feature of solid flow, and that it is affected strongly by gas flow. However, it is difficult to model this feature within the framework of continuum mechanics without empirical or arbitrary treatments. This paper reports the use of discrete particle simulation fo...

To monitor the gas and solid streams in a downcomer of a J-valve in a CFB, the simultaneous measurement technique using the oxygen gas tracer, the hot particle tracer and the pressure drop was developed. By using this novel measurement technique, the dependence of the solid flow on the gas flow in the moving bed in the downcomer of J-valve was investigated. The pressure profile and the pressure...

Molecular dynamics simulations were performed for CO2 dissolved in water near silica surfaces to investigate how the hydrophilicity and crystallinity of solid surfaces modulate the local structure of adjacent molecules and the nucleation of CO2 hydrates. Our simulations reveal that the hydrophilicity of solid surfaces can change the local structure of water molecules and gas distribution near l...