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.

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.

scholarly journals Feasible Concept of an Air-Driven Fan with a Tip Turbine for a High-Bypass Propulsion System

Energies ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 3350 ◽  
Author(s):  
Guoping Huang ◽  
Xin Xiang ◽  
Chen Xia ◽  
Weiyu Lu ◽  
Lei Li
Keyword(s):  
Fluid Dynamics ◽  
Carbon Dioxide Emissions ◽  
Three Dimensional ◽  
Propulsion System ◽  
Navier Stokes ◽  
Three Dimensional Flow ◽  
Low Pressure Turbine ◽  
Computational Fluid Dynamics Cfd ◽  
Cfd Method ◽  
Bypass Ratio

The reduction in specific fuel consumption (SFC) is crucial for small/mid-size cost-controllable aircraft, which is very conducive to reducing cost and carbon dioxide emissions. To decrease the SFC, increasing the bypass ratio (BPR) is an important way. Conventional high-BPR engines have several limitations, especially the conflicting spool-speed requirements of a fan and a low-pressure turbine. This research proposes an air-driven fan with a tip turbine (ADFTT) as a potential device for a high-bypass propulsion system. Moreover, a possible application of this ADFTT is introduced. Thermodynamic analysis results show that an ADFTT can improve thrust from a prototype turbofan. As a demonstration, we selected a typical small-thrust turbofan as the prototype and applied the ADFTT concept to improve this model. Three-dimensional flow fields were numerically simulated through a Reynolds averaged Navier-Stokes (RANS)-based computational fluid dynamics (CFD) method. The performance of this ADFTT has the possibility of amplifying the BPR more than four times and increasing the thrust by approximately 84% in comparison with the prototype turbofan.

Simulation of Three-Dimensional Flow Field Around Unconventional Bridge Piers

2017 ◽  
Author(s):  
Adnan Ismael ◽  
Hamid Hussein ◽  
Mohammed Tareq ◽  
Mustafa Gunal
Keyword(s):  
Flow Field ◽  
Three Dimensional ◽  
Bridge Piers ◽  
Three Dimensional Flow ◽  
Dimensional Flow

Experimental investigation on the three-dimensional flow field from a meltblowing slot die

e-Polymers ◽  
2020 ◽  
Vol 20 (1) ◽  
pp. 724-732
Author(s):  
Changchun Ji ◽  
Yudong Wang
Keyword(s):  
Flow Field ◽  
Three Dimensional ◽  
Great Influence ◽  
Distribution Characteristics ◽  
Air Velocity ◽  
Three Dimensional Flow ◽  
Dimensional Flow ◽  
Airflow Distribution ◽  
Slot Die ◽  
Center Area

AbstractTo investigate the distribution characteristics of the three-dimensional flow field under the slot die, an online measurement of the airflow velocity was performed using a hot wire anemometer. The experimental results show that the air-slot end faces have a great influence on the airflow distribution in its vicinity. Compared with the air velocity in the center area, the velocity below the slot end face is much lower. The distribution characteristics of the three-dimensional flow field under the slot die would cause the fibers at different positions to bear inconsistent air force. The air velocity of the spinning centerline is higher than that around it, which is more conducive to fiber diameter attenuation. The violent fluctuation of the instantaneous velocity of the airflow could easily cause the meltblowing fiber to whip in the area close to the die.

scholarly journals Transient Three-Dimensional Flow Field Measurements by Means of 3D µPTV in Drying Poly(Vinyl Acetate)-Methanol Thin Films Subject to Short-Scale Marangoni Instabilities

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1223
Author(s):  
Max Tönsmann ◽  
Philip Scharfer ◽  
Wilhelm Schabel
Keyword(s):  
Flow Field ◽  
Vinyl Acetate ◽  
Three Dimensional ◽  
Field Measurements ◽  
Initial Assessment ◽  
Ambient Conditions ◽  
Three Dimensional Flow ◽  
Dimensional Flow ◽  
Short Scale ◽  
Dry Film

Convective Marangoni instabilities in drying polymer films may induce surface deformations, which persist in the dry film, deteriorating product performance. While theoretic stability analyses are abundantly available, experimental data are scarce. We report transient three-dimensional flow field measurements in thin poly(vinyl acetate)-methanol films, drying under ambient conditions with several films exhibiting short-scale Marangoni convection cells. An initial assessment of the upper limit of thermal and solutal Marangoni numbers reveals that the solutal effect is likely to be the dominant cause for the observed instabilities.

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