Investigation on Laminar Flow Field Performances in a Dual-Impeller Stirred Tank

2012 ◽  
Vol 550-553 ◽  
pp. 2964-2967
Author(s):  
De Yu Luan ◽  
Shen Jie Zhou ◽  
Song Ying Chen
Keyword(s):  
Laminar Flow ◽  
Flow Field ◽  
Velocity Distribution ◽  
Radial Velocity ◽  
Velocity Vector ◽  
Equations Of Motion ◽  
Stirred Tank ◽  
Field Pattern ◽  
3D Flow ◽  
Multiple Reference

Abstract: The 3D flow field generated by a dual-impeller in the agitation of glycerin fluid was simulated using the commercial CFD package. The flow was modeled as laminar and a multiple reference frame (MRF) approach was used to solve the discretized equations of motion. The velocity profiles with a dual-impeller rotating at constant speed of 200r/min and at different layer clearances were obtained. By analysis to their axial and radial velocity vector plots and velocity distribution curves, it is found that the velocity distributions of the dual 6-bladed radial disc turbines (2-6DT) are better when the clearance is bigger or equal to the T/2, accompanied with the flow field pattern of parallel flow. Moreover，when the clearance is smaller or equal to the T/3, there are more advantages for 6-bladed radial disc turbines + pitch 4-bladed turbines (6DT+PTB) than other combinations，followed by the flow field pattern of connected flow.

Numerical Simulation of Laminar Flow Field in a Stirred Tank with a Rushton Impeller or a Pitch 4-Bladed Turbine

2012 ◽  
Vol 557-559 ◽  
pp. 2375-2382
Author(s):  
Jun Ling Fan ◽  
De Yu Luan
Keyword(s):  
Laminar Flow ◽  
Flow Field ◽  
Equations Of Motion ◽  
Flow Characteristics ◽  
Stirred Tank ◽  
High Power Consumption ◽  
Computational Fluid Dynamics Cfd ◽  
Cfd Method ◽  
Multiple Reference ◽  
Rushton Impeller

Computational fluid dynamics (CFD) method was applied to the study of flow field in the agitation of glycerin fluid with a Rushton impeller and a pitch 4-bladed turbine. The flow was modeled as laminar and a multiple reference frame (MRF) approach was used to solve the discretized equations of motion. The velocity profiles predicted by the simulation with four different impellers rotating at constant speed of 200r/min were obtained. By analysis to their axial, radial and tangent velocity vector plots, velocity contours and velocity distribution curves, it was found that the stirred effect of the Rushton impeller was better than one of the pitch 4-bladed turbines，however，accompanied with high power consumption according to the calculated values of required power. Moreover, there were all similar flow characteristics for the pitch 4-bladed turbines with different blade pitch angle. The research provided a theoretical basis for the design and practical application of the stirred tank under laminar flow.

Numerical Simulation of the Laminar Flow Field in Stirred Tank with Double Layer Combined Impeller Stirring Eccentrically

2015 ◽  
Vol 779 ◽  
pp. 125-132
Author(s):  
Ying Na Liang
Keyword(s):  
Flow Field ◽  
Double Layer ◽  
Three Dimensional ◽  
Stirred Tank ◽  
Flow Structures ◽  
Practical Application ◽  
Three Dimensional Flow ◽  
Computational Fluid Dynamics Cfd ◽  
Cfd Method ◽  
Multiple Reference

Computational fluid dynamics (CFD) method was applied to study the flow field in cylindrical stirred tank mixing non-Newtonian fluid with double layer combined impeller of upper-straight-blade and lower-inclined-blade. The laminar model and the multiple reference frame (MRF) were employed to simulate the three-dimensional flow field in stirred tank with double layer combined impeller rotating at a constant speed of 200 r/min mixing the mixture of glycerin and water centrally、eccentrically and relative eccentrically, and three different flow structures in stirred tank were obtained. Analyzing the velocity vectors, the velocity contours and the axial、radial and tangent velocity distribution curves, the rule of velocity field with the blade combined form and the stirring structure was discussed. The research provided the valuable reference for the design and practical application of the laminar stirred tank.

Inward Flow Between Stationary and Rotating Disks

2014 ◽  
Vol 136 (10) ◽  
Author(s):  
Achhaibar Singh
Keyword(s):  
Laminar Flow ◽  
Flow Field ◽  
Velocity Distribution ◽  
Stokes Equations ◽  
Tangential Velocity ◽  
Rotating Disk ◽  
Reynolds Numbers ◽  
Navier Stokes ◽  
Rotating Disks ◽  
Navier Stokes Equations

The present study predicts the flow field and the pressure distribution for a laminar flow in the gap between a stationary and a rotating disk. The fluid enters through the peripheral gap between two concentric disks and converges to the center where it discharges axially through a hole in one of the disks. Closed form expressions have been derived by simplifying the Navier– Stokes equations. The expressions predict the backflow near the rotating disk due to the effect of centrifugal force. A convection effect has been observed in the tangential velocity distribution at high throughflow Reynolds numbers.

An Effect of Fractal Baffles and Impellers with Double Stage 4-Blade Rushton Turbine to Fluid Flow Behaviour in Stirred Tank

2014 ◽  
Vol 660 ◽  
pp. 816-822 ◽  
Author(s):  
Bukhari Manshoor ◽  
Afifah Yusof ◽  
Suraya Laily ◽  
Izzuddin Zaman ◽  
Amir Khalid
Keyword(s):  
Flow Field ◽  
High Velocity ◽  
Velocity Vector ◽  
Fluid Mixing ◽  
Stirred Tank ◽  
Mixing Efficiency ◽  
Rushton Turbine ◽  
Fractal Pattern ◽  
Piv Technique ◽  
Piv Measurement

The stirred tank is widely used in many industries to obtain the desired type of fluid mixing. In the context of mixing process, two different fluids and have a different properties will mix in a single equipment to produce another fluid with a new property. In this research, a new approach of stirred tank which is containing a new design of baffles and impellers was proposed for fluid mixing. The new design of baffles and impellers that proposed here are used a fractal pattern for both parts in the stirred tank. Implementing a fractal pattern for baffles and impellers in stirred tank believe will influence the flow characteristic inside the stirred tank, hence will improve a mixing performance. In order to investigate the kinds of flow properties, a Particle Image Velocimetry (PIV) technique with 1 μm seeding particle was used. Four configurations were tested which are normal baffles and normal impellers, normal baffles and fractal impellers, fractal baffles and normal impellers, and the last configuration is fractal baffles and fractal impellers. In this study, dual Rushton impellers with 4 blades were used with the configurations mentioned. The result shows the significant flow field capture by PIV measurement on each configuration. By using fractal impeller some vortex are shown in the tank and high velocity vector on flow field compare with normal impeller while normal baffles gives high velocity vector depends on the configuration were used. From the results, it was showed that the fractal design can give a certain level of mixing efficiency in stirred tank. The PIV technique also gives good flow visualization in order to determine the flow pattern in stirred tank with a new concept of baffles and impellers.

The Influence of Burner Nozzle Angle for Flow Field and Heat Transfer of Ultra-Supercritical Tower Boiler

2011 ◽  
Author(s):  
Saike Chen ◽  
Mo Yang ◽  
Yuwen Zhang ◽  
Zhangyang Kang
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Theoretical Analysis ◽  
Flow Field ◽  
Velocity Distribution ◽  
Velocity Vector ◽  
Flow Model ◽  
Simple Algorithm ◽  
Quick Scheme ◽  
Burner Nozzle

The angle of burner nozzle is an important factor for burning of ultra-supercritical tower boiler. In this paper, gassolid multiphase flow and combustion in 1000MW Ultra-supercritical tower furnace were of the numerical simulation under different conditions. The angle of burner nozzle deflects downward, and the angle is 0°, 3°, 6°, 9° and 12°. Flow model is turbulence and SIMPLE algorithm and QUICK scheme are employed. Through theoretical analysis of different conditions (the velocity distribution in different face; the velocity vector in furnace; the temperature in furnace; the NOx, CO2 and O2 emissions in outlet), finally, the law of the angle of burner nozzle for flow field and heat transfer in ultra-supercritical tower boiler is found.

Numeric Investigation of an Axi-Symmetric Turbulent Jet

2014 ◽  
Author(s):  
Mohammad A. Hossain ◽  
Sarzina Hossain
Keyword(s):  
Experimental Data ◽  
Flow Field ◽  
Velocity Distribution ◽  
Radial Velocity ◽  
Axial Velocity ◽  
Turbulent Jet ◽  
Field Analysis ◽  
Turbulent Dissipation ◽  
Round Jet ◽  
Research Areas

This work is focused on a numerical investigation of a turbulent axi-symmetric round jet in order to incorporate the knowledge of turbulence. Flow field analysis of a turbulent jet is one of the major research areas in recent years as turbulent jet dictates the interaction between fluid and other physical phenomena. Heat transfer, natural convection, frame propagation all depend on the behavior of turbulent jet. The mass and momentum transfer phenomena governs the flow field of the jet. A two dimensional pressure based Navier-stock solver is used to resolve the flow parameter of a turbulent round jet. Around One hundred twenty five thousand quadratic mesh elements are used for the simulation. A Mesh independency test has been done before resolving results. Characteristic flow parameters such as mean axial velocity, mean radial velocity distribution, turbulent kinetic energy, turbulent intensity, the turbulent dissipation rate are determined and presented. Similarity solution for mean axial velocity distribution and mean radial velocity distribution at different axial location are calculated and compared with experimental data. The result shows good agreement with experimental data.

scholarly journals Moving Object Detection by 3D Flow Field Analysis

2021 ◽  
Vol 22 (4) ◽  
pp. 1950-1963
Author(s):  
Cansen Jiang ◽  
Danda Pani Paudel ◽  
David Fofi ◽  
Yohan Fougerolle ◽  
Cedric Demonceaux
Keyword(s):  
Flow Field ◽  
Object Detection ◽  
Moving Object Detection ◽  
Moving Object ◽  
Field Analysis ◽  
3D Flow ◽  
Flow Field Analysis

Contrast Study on the Radial Velocity of the Flow Field of the Hydrocyclones with Different Inlet Structures

2011 ◽  
Vol 339 ◽  
pp. 624-629
Author(s):  
Lian Cheng Ren ◽  
Zheng Liang ◽  
Jiang Meng ◽  
Lin Yang ◽  
Jia Lin Tian
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Radial Velocity ◽  
Axial Symmetry ◽  
Separation Efficiency ◽  
Great Influence ◽  
The Other ◽  
Contrast Study ◽  
The One ◽  
Tangential Inlet

On the base of numerical simulation and theoretical analysis, the flow field of a conventional single-tangential-inlet Hydrocyclone and a newly put forward axial-symmetry double-tangential-inlet hydrocyclone were contrasted. The study shows that the inlet structure of the Hydrocylone has a great influence on the radial velocity of the flow field in the hydrocyclone and that the radial velocity in the hydrocyclone with single-tangential-inlet is not symmetry about the axis of the hydrocyclone; and on the other hand the radial velocity in the hydrocyclone with axial-symmetry double-tangential-inlet is symmetry about the axis of the hydrocyclone. The magnitude of the radial velocity of the flow in the hydrocyclone with single-tangential-inlet is greater than that in the hydrocyclone with axial-symmetry double-tangential-inlet hydrocyclone, which means the hydrocyclone with axial-symmetry double-tangential-inlet has greater capability than the rival one with single-tangential inlet. The symmetry about the axis of the hydrocyclone of the radial velocity means the radial velocities in the place where the radio is the same are constant, which means the hydrocyclone has a great separation efficiency. The conclusion is that changing the conventional hydrocyclone into the one with axial-symmetry double-tangential-inlet structure can offer greater separation capability and efficiency.

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