A 3D CFD simulation of a self inducing Pitched Blade Turbine Downflow

Achouri, Ryma; Mokni, Ines; Mhiri, Hatem; Bournot, Philippe

doi:10.1016/j.enconman.2012.06.005

Cited by 35 publications

(17 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In this regard, the turbulence modelling based on the Reynolds average Navier-Stokes equations (RANS) is a more suitable option for practical engineering applications (Andersson et al, 2012). Further, just to point out two examples, LES sub-grid scale models (SGS) for multiphase flow, and those related to thermally affected boundary layers are not fully understood (Jiang and Lai, 2009), and engineering design simulations still rely on RANS modelling (Achouri et al, 2012;Ge et al, 2014;Kasat et al, 2008). Over the last two decades, a variety of works have been devoted to study the flow in STRs using RANS based turbulence models by means of the Multiple Reference Frame (MRF) and the Sliding mesh (SM) approaches mainly for Rushton turbines, PBT impellers and others.…”

Section: Introductionmentioning

confidence: 99%

On the Performance of Different Rans Based Models to Describe the Turbulent Flow in an Agitated Vessel Using Non-Structured Grids and Piv Validation

Alonzo-García

Mendoza-Escamilla

Martínez-Delgadillo

et al. 2019

Braz. J. Chem. Eng.

View full text Add to dashboard Cite

The performances of the Standard κ-ε, RNG, Realizable, κ-w and RSM turbulence models to describe the behavior of the flow in agitated tank reactors were evaluated. Because most of these tanks have complex geometries, structured meshing schemes are not a practical alternative in engineering. Two particular unstructured meshing schemes composed of either Cartesian Cut-Cell (CC) or Tetrahedral elements were tested in domains larger than 3 million cells. In this work, the blade thickness, which is usually disregarded, was accounted for. The performance of the turbulence models was validated by PIV measurements. A strong dependence on the grid size and the power number was found, with CC grids having good agreement with grids > 3.6 Million. The pumping number was independent of the cell number and the values agree with experimental data. The Realizable model resolved with a tetrahedral grid presented the overall best performance.

show abstract

Section: Introductionmentioning

confidence: 99%

On the Performance of Different Rans Based Models to Describe the Turbulent Flow in an Agitated Vessel Using Non-Structured Grids and Piv Validation

Alonzo-García

Mendoza-Escamilla

Martínez-Delgadillo

et al. 2019

Braz. J. Chem. Eng.

View full text Add to dashboard Cite

show abstract

“…Only a few researchers used CFD to study the flow field characteristics in self-inducing gasliquid stirred tanks. [16][17][18][19] Murthy et al, [16] for example, numerically modelled gas-liquid flow field characteristics in a tank stirred by a self-inducing pitched blade turbine. In the simulations, the gas induction rate was calculated using an iterative method.…”

Section: Introductionmentioning

confidence: 99%

“…A two-step simulation method was carried out, i.e., single phase simulations for hollow shaft and impeller and two phase simulations for the stirred tank. For the same tank as that modelled by Murthy et al, [16] Achouri et al [17] simulated the gas-liquid dispersion in the tank considering all the fluid domains as a whole. The simulation results of gas induction rate and power number have been compared with experimental data.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

CFD simulation of hydrodynamics characteristics in a tank stirred by a hollow self‐inducing impeller

Chen²,

Ke-feng

et al. 2018

Can J Chem Eng

View full text Add to dashboard Cite

Hollow self-inducing impellers are often used in gas-liquid stirred tanks in many industrial processes. To understand the hydrodynamics characteristics of this type of stirred tank under aerated and unaerated conditions, a computational fluid dynamics (CFD) simulation study was conducted. The predicted gas self-inducing flow rate, power consumption, and impeller power number were compared with the experimental data in the literature and discussed. Under unaerated conditions, liquid level in the hollow shaft relies on the impeller speed, and is slightly influenced by the impeller clearance. Self-inducing impeller power number remains almost unchanged with impeller speed, while increasing with the rise of the impeller clearance. Under aerated conditions, gas is easy to accumulate in the centre of the upper and lower circulation loops. Gas self-inducing flow rate, global gas holdup, and power consumption increase with higher impeller speed. The critical impeller speed for gas self-induction decreases with higher impeller clearance. At the same impeller speed, gas self-inducing flow rate and global gas holdup increase, while power consumption reduces with increasing of impeller clearance.

show abstract

“…In addition, high viscosity of lignocellulose slurry constrains mixing results, and the impeller is the main structure that determines the mixing effect and power consumption. Many impeller designs are mainly focused on optimization of height‐to‐tank diameter ratio, impeller types such as energy efficiency on pitched blades, helical ribbon impeller and Rushton and others, and operation conditions like critical stirring speed are investigated . Ahead of developing an appropriate reactor, the rheological properties of the enzymatic hydrolysis slurry should be studied .…”

Section: Introductionmentioning

confidence: 99%

A novel quasi plug‐flow reactor design for enzymatic hydrolysis of cellulose using rheology experiment and CFD simulation

Cao

Geng

et al. 2017

Can J Chem Eng

View full text Add to dashboard Cite

One of the obstacles constraining bio‐ethanol production using cellulose is enzymatic hydrolysis. Uniform distribution of slurry residence time is important to improve the efficiency. Efforts were made to develop a novel quasi plug‐flow reactor on industrial scale for enzymatic hydrolysis of cellulose by CFD simulation. Ahead of numerical simulation, the rheological properties of the cellulose enzymolysis slurry of furfural residues were studied based on experiments. A turbulence model called k‐kl‐ω was employed in CFD simulation, which was good at describing the flow field with great variation on the extent of turbulence in the stirred tank. Vertical blades, pitched blades, helical ribbons, and their combination were investigated firstly, and then the internal structures were optimized. The calculated residence time distribution curve showed that the quasi plug‐flow reactor had the following features: (1) combination of double helical ribbons and vertical blade, (2) two partitions and four baffles, (3) flow area was 0.1 m2 on partitions. The CFD simulation methods and results could provide a theoretical guidance for the development of a novel quasi plug‐flow reactor to improve the efficiency of the cellulose enzymatic hydrolysis on industrial scale.

show abstract

A 3D CFD simulation of a self inducing Pitched Blade Turbine Downflow

Cited by 35 publications

References 18 publications

On the Performance of Different Rans Based Models to Describe the Turbulent Flow in an Agitated Vessel Using Non-Structured Grids and Piv Validation

On the Performance of Different Rans Based Models to Describe the Turbulent Flow in an Agitated Vessel Using Non-Structured Grids and Piv Validation

CFD simulation of hydrodynamics characteristics in a tank stirred by a hollow self‐inducing impeller

A novel quasi plug‐flow reactor design for enzymatic hydrolysis of cellulose using rheology experiment and CFD simulation

Contact Info

Product

Resources

About