Computational Fluid Dynamics Applied to Bradley Hydrocyclones

2006 ◽  
Vol 530-531 ◽  
pp. 376-381 ◽  
Author(s):  
Luiz Gustavo Martins Vieira ◽  
João Jorge Ribeiro Damasceno ◽  
Marcos A.S. Barrozo
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Fluid Model ◽  
Reynolds Stress Model ◽  
Operational Conditions ◽  
Air Core ◽  
Volume Of Fluid Model ◽  
Computational Fluid Dynamics Cfd ◽  
Geometric Variables ◽  
Solid Liquid

Hydrocyclones are centrifugal devices employed on the solid-liquid and liquid-liquid separation. The operation and building of these devices are relatively simple, however the flow inside them is totally complex and its prediction is very difficult. The fluid moves on all possible directions (axial, radial and swirl), the effects of turbulence can not negligible and an air core along the center line of the hydrocyclone can appear when the operational conditions are favorable. For that reason, the most models that are used to predict the hydrocyclone performance are empirical and require the collection of the main operational and geometric variables in order to validate them. This work objectified to apply Computational Fluid Dynamics (CFD) on Bradley Hydrocyclone and compare the results from this technique to empirical models. The numerical simulation was made in a computational code called Fluent® that solves the transport equation by finite volume technique. The turbulence was described by Reynolds Stress Model (RSM) and the liquid-gas interface was treated by Volume of Fluid Model (VOF). In agreement with the results from the simulation, it was possible to predict the internal profiles of velocity, pressure, air core, particle trajectories, efficiencies, pressure drop and underflow-to-throughput ratio.

Computational Fluid Dynamics Applied to Bradley Hydrocyclones

2005 ◽  
Vol 498-499 ◽  
pp. 264-269
Author(s):  
Luiz Gustavo Martins Vieira ◽  
João Jorge Ribeiro Damasceno ◽  
Marcos A.S. Barrozo
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Fluid Model ◽  
Reynolds Stress Model ◽  
Operational Conditions ◽  
Air Core ◽  
Volume Of Fluid Model ◽  
Computational Fluid Dynamics Cfd ◽  
Geometric Variables ◽  
Solid Liquid

Hydrocyclones are centrifugal devices employed on the solid-liquid and liquid-liquid separation. The operation and building of these devices are relatively simple, however the flow inside them is totally complex and its prediction is very difficult. The fluid moves on all possible directions (axial, radial and swirl), the effects of turbulence can not negligible and an air core along the center line of the hydrocyclone can appear when the operational conditions are favorable. For that reason, the most models that are used to predict the hydrocyclone performance are empirical and require the collection of the main operational and geometric variables in order to validate them. This work objectified to apply Computational Fluid Dynamics (CFD) on Bradley Hydrocyclone and compare the results from this technique to empirical models. The numerical simulation was made in a computational code called Fluent® that solves the transport equation by finite volume technique. The turbulence was described by Reynolds Stress Model (RSM) and the liquid-gas interface was treated by Volume of Fluid Model (VOF). In agreement with the results from the simulation, it was possible to predict the internal profiles of velocity, pressure, air core, particle trajectories, efficiencies, pressure drop and underflow-to-throughput ratio.

scholarly journals Biphasic Computational Fluid Dynamics Modelling of the Mixture in an Agricultural Sprayer Tank

Molecules ◽  
2020 ◽  
Vol 25 (8) ◽  
pp. 1870
Author(s):  
Jorge Badules ◽  
Mariano Vidal ◽  
Antonio Boné ◽  
Emilio Gil ◽  
F. Javier García-Ramos
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Computer Simulations ◽  
Fluid Model ◽  
Standard Procedure ◽  
Theoretical Models ◽  
Physical Models ◽  
Discrete Phase Model ◽  
Discrete Phase ◽  
Volume Of Fluid Model

Agitation inside agricultural sprayer tanks can be studied while using an international standard procedure, based on obtaining internal samples of liquid. However, in practice, this test is not easy to perform. Herein, we propose the explicit study of the mixing procedure with biphasic computer simulations using Computational Fluid Dynamics (CFD). An experimental test was performed on a 3000 L tank of a commercial air-assisted sprayer, with two different agitation system configurations, in order to compare the results of several theoretical physical models of biphasic flows for CFD, both Eulerian and Lagrangian. From the analysis of these theoretical models, we conclude that the Volume of Fluid model is not viable and the Discrete Phase Model produces erroneous results, while the Eulerian and Mixture models can both be useful. However, the results obtained suggest that complex streams generated by real-world agitation systems produce more errors in calculations. Both models can be conducted in the design phase, prior to the implementation of the machine. In addition, the computer simulations allow for researchers to analyse the mixing process in detail, making it possible to evaluate the efficiency of an agitation system according to the time that is required to reach mixture homogeneity.

scholarly journals Performance Analysis and Modeling of Microplastic Separation through Hydro Cyclones

2021 ◽  
Author(s):  
Fabio Borgia
Keyword(s):  
Fluid Dynamics ◽  
Mathematical Model ◽  
Computational Fluid Dynamics ◽  
Cfd Modeling ◽  
Separation Device ◽  
Operation Conditions ◽  
Computational Fluid Dynamics Cfd ◽  
Solid Liquid ◽  
Solid Liquid Separation ◽  
The Mathematical Model

The filtering hydro cyclone is a solid–liquid separation device, generally conical in shape. The hydro cyclone allows the separation of microplastics from water, to facilitate micro-recycling. To test the capabilities of a hydro cyclone at separating microplastics from water, Rietema’s standard sizes, mathematical and computational fluid dynamics (CFD) modeling were used. The results show that, even dough the mathematical model in unreliable when considering parameters out-side standard operation conditions, hydro cyclone microplastic separation can be achieved at 98% efficiency. Particles reach the outlet on average in 1.5 s for a flow velocity of 2 m/s, and denser microplastics end up in the underflow.

A Computational Fluid Dynamics (CFD) Study of Material Flow in Pneumatic Microextrusion (PME) Additive Manufacturing Process

2020 ◽  
Author(s):  
Ye Jien Yeow ◽  
Mohan Yu ◽  
James B. Day ◽  
Roozbeh (Ross) Salary
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Gas Flow ◽  
Fluid Model ◽  
Accurate Solution ◽  
Sensor Data ◽  
Cfd Model ◽  
Transient Pressure ◽  
Material Transport ◽  
Computational Fluid Dynamics Cfd

Abstract The objective of this study is to investigate the underlying physical phenomena behind material transport in pneumatic micro-extrusion (PME) process, using a computational fluid dynamics (CFD) model. The geometry of the PME deposition head assembly (including a micro-capillary having a diameter of 200 μm) was set up in the ANSYS-Fluent environment, based on a patented design in addition to direct measurements of the dimensions of the assembly. Subsequently, the geometry was meshed using tetrahedron cells. Besides, five layers of inflation were defined with the aim to obtain an accurate solution near all wall boundaries. The transient, pressure-based Navier-Stokes algorithm (based on absolute velocity formulation) was the mathematical model of choice, used to obtain transient solutions. To account for the effects of compressibility as well as viscose heating, the energy equation (in addition to the continuity and momentum equations) was utilized in the CFD model. Furthermore, the explicit volume of fluid model (composed of two Eulerian phases) and the laminar viscose model were used to collectively establish a viscose two-phase flow model for the molten polymer (PCL) deposition in the PME process. Pressure-velocity coupling was implemented using the semi-implicit method for pressure linked equations (SIMPLE). Finally, experimental sensor data was used with the aim to: (i) define the boundary conditions (as follows), and (ii) validate the CFD model. In this study, PCL powder was loaded into the cartridge, maintained at 120 °C, defined as the temperature of all stationery walls (with no slip condition). Pressure inlet was the type of boundary defined for the high-pressure gas flow in the PME process, set at 550 kPa. The laminar molten PCL flow was deposited on a glass substrate, steadily and uniformly kept at 45 °C, defined as the temperature of the substrate wall, moving with a speed of 0.35 mm/s. Overall, the results of this study pave the way for better understanding of the causal phenomena behind material transport and deposition in the PME process toward fabrication of bone tissue scaffolds with optimal functional properties.

Scaled Room Three-Dimensional Computational Fluid Dynamics Simulations

2002 ◽  
Author(s):  
Steven P. O’Halloran ◽  
Mohammad H. Hosni ◽  
B. Terry Beck ◽  
Thomas P. Gielda
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Three Dimensional ◽  
Turbulence Models ◽  
Reynolds Stress Model ◽  
Working Fluid ◽  
Image Velocimetry ◽  
Computational Fluid Dynamics Simulations ◽  
Computational Fluid Dynamics Cfd ◽  
Dynamics Simulations

Computational fluid dynamics (CFD) simulations were used to predict three-dimensional flow within a one-tenth-scale room. The dimensions of the scaled room were 732 × 488 × 274 mm (28.8 × 19.2 × 10.8 in.) and symmetry was utilized so that only half of the room was modeled. Corresponding measurements were made under isothermal conditions and water was used as the working fluid instead of air. The commercially available software Fluent was used to perform the simulations. Two turbulence models were used: the renormalization group (RNG) k-ε model and the Reynolds-stress model. The CFD setup is presented in this paper, along with the velocity and turbulent kinetic energy results. The simulation results are compared to previously obtained three-dimensional particle image velocimetry (PIV) measurements made within the same scaled room under similar conditions.

Numerical Simulations of Gas-Liquid-Solid Flows in a Hydrocyclone Separator

2007 ◽  
Author(s):  
S. M. Musavian ◽  
A. F. Najafi
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Reynolds Stress ◽  
Separation Efficiency ◽  
Flow Behavior ◽  
Tangential Velocity ◽  
Reynolds Stress Model ◽  
Multiphase Model ◽  
Air Core ◽  
Cfd Method

The flow behavior in hydrocyclones is quite complex. The Computational Fluid Dynamics (CFD) method was used to simulate the flow fields inside a hydrocyclone in order to improve its separation efficiency. In the computational fluid dynamics study of hydrocyclones, the air-core dimension is a key to predicting the mass split between the underflow and overflow. In turn, the mass split influences the prediction of the size classification curve. Three models, the k–e model, the Reynolds stress model without considering air core and Reynolds stress turbulence model with VOF multiphase model for simulating aircore, were compared for the predictions of velocity, axial and tangential velocity distributions and separation proportion. The RSM with aircore simulation model, since it produces some detailed features of the turbulence and multi phase, is clearly closer in predicting the experimental data than the other two.

Application of CFD in the Study of Performance the Cyclone with Different Shapes

2010 ◽  
Vol 660-661 ◽  
pp. 515-519
Author(s):  
A.F. Lacerda ◽  
R.O. Lourenço ◽  
E.N. Macêdo
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Numerical Solutions ◽  
Reynolds Stress Model ◽  
Gas Streams ◽  
Computational Fluid Dynamics Cfd ◽  
Different Shapes ◽  
Dust Loading ◽  
Temperature And Pressure ◽  
Very High

Gas cyclone separators are widely used in industrial processes for separation of dust from gas streams or for product recovery. Their design normally has tangential entrance inlets and the cyclones are defined as funnel-shaped industrial inertial devices. Cyclones are particularly well suited for high temperature and pressure conditions because of their rugged design and flexible components materials. Cyclone collection efficiencies can reach 99% for particles bigger than 5 μm, and can be operated at very high dust loading. One of the aims of this research was simulate, through computational fluid dynamics (CFD), the operation of the cyclones with different geometrics and to analyze the influence its different geometrics in the performance of the cyclones. The numerical solutions were carried out using commercial CFD. A two-dimensional computational fluid dynamics (CFD) Reynolds stress model (RSM) was used to describe the gas–solid flow in cyclones.

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