scholarly journals RESEARCH ON NUMERICAL SIMULATION FOR VELOCITY DISTRIBUTION OF SWIRLING TURBULENT JETS IN SPRAY IRRIGATION TECHNOLOGY

2010 ◽  
Vol 13 (2) ◽  
pp. 93-99
Author(s):  
Tuyen Vo ◽  
Nam Thanh Nguyen
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Tangential Velocity ◽  
Turbulent Jets ◽  
Intensity Coefficient ◽  
Irrigation Technology ◽  
Swirl Intensity ◽  
Intensity Changes ◽  
Basic Parameters ◽  
Spray Irrigation

In spray irrigation technology, the change of the basic parameters of the flowfteld has relationship directly with the coefficient of swirling intensity coefficient s, with each value of swirling coefficient differently then the distribution of parameters in flow field also variedly. Remarkably change when the coefficient of swirl intensity changes through the variables as axial velocity u, tangential velocity w; the change of radial velocity V related to turbulent intensity.

scholarly journals Experimental and CFD Studies of the Hydrodynamics in Wet Agglomeration Process

2018 ◽  
Vol 2 (3) ◽  
pp. 32 ◽  
Author(s):  
Benjamin Oyegbile ◽  
Guven Akdogan ◽  
Mohsen Karimi
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Flow Analysis ◽  
Outer Region ◽  
Tangential Velocity ◽  
Numerical Code ◽  
Cfd Model ◽  
Rotating Disc ◽  
Batch Mode ◽  
Agglomeration Process

In this study, an experimentally validated computational model was developed to investigate the hydrodynamics in a rotor-stator vortex agglomeration reactor RVR having a rotating disc at the centre with two shrouded outer plates. A numerical simulation was performed using a simplified form of the reactor geometry to compute the 3-D flow field in batch mode operations. Thereafter, the model was validated using data from a 2-D Particle Image Velocimetry (PIV) flow analysis performed during the design of the reactor. Using different operating speeds, namely 70, 90, 110, and 130 rpm, the flow fields were computed numerically, followed by a comprehensive data analysis. The simulation results showed separated boundary layers on the rotating disc and the stator. The flow field within the reactor was characterized by a rotational plane circular forced vortex flow, in which the streamlines are concentric circles with a rotational vortex. Overall, the results of the numerical simulation demonstrated a fairly good agreement between the Computational Fluid Dynamics (CFD) model and the experimental data, as well as the available theoretical predictions. The swirl ratio β was found to be approximately 0.4044, 0.4038, 0.4044, and 0.4043 for the operating speeds of N = 70, 90, 110, and 130 rpm, respectively. In terms of the spatial distribution, the turbulence intensity and kinetic energy were concentrated on the outer region of the reactor, while the circumferential velocity showed a decreasing intensity towards the shroud. However, a comparison of the CFD and experimental predictions of the tangential velocity and the vorticity amplitude profiles showed that these parameters were under-predicted by the experimental analysis, which could be attributed to some of the experimental limitations rather than the robustness of the CFD model or numerical code.

Numerical Simulation of Flow Field in Bloom Continuous Casting Mold with Electromagnetic Stirring

2010 ◽  
Vol 146-147 ◽  
pp. 272-276 ◽  
Author(s):  
Jing Zhang ◽  
En Gang Wang ◽  
An Yuan Deng ◽  
Xiu Jie Xu ◽  
Ji Cheng He
Keyword(s):  
Magnetic Field ◽  
Numerical Simulation ◽  
Flow Field ◽  
Continuous Casting ◽  
Tangential Velocity ◽  
Electromagnetic Stirring ◽  
Continuous Casting Mold ◽  
Frequency Increase ◽  
Velocity Increase ◽  
Casting Mold

A coupled numerical simulation of magnetic field and flow field was conducted basing on Φ250mm bloom during continuous casting with electromagnetic stirring.The distribution of the flow field was analyzed in different current and frequency.At the same current,the velocity first decrease and then increase as the frequency increase along the casting direction.At the same frequency, tangential velocity is dominant in the radial of EMS center,velocity increase with the current. Considered the results of numerical simulation,the optimized EMS parameters of Φ250mm bloom are the stirring current of 480A and the stirring frequency of 3Hz.

scholarly journals Experimental Study and Hydrodynamic Modelling of the Wet Agglomeration Process

2018 ◽  
Author(s):  
Benjamin Oyegbile ◽  
Guven Akdogan ◽  
Mohsen Karimi
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Flow Analysis ◽  
Outer Region ◽  
Tangential Velocity ◽  
Numerical Code ◽  
Cfd Model ◽  
Rotating Disc ◽  
Batch Mode ◽  
Agglomeration Process

In this study, an experimentally validated computational model was developed to investigate the hydrodynamics in a rotor-stator vortex RVR agglomeration reactor having a rotating disc at the centre with two shrouded outer plates. A numerical simulation was performed using a simplified form of the reactor geometry to compute the 3D flow field in batch mode operations. Thereafter, the model was validated using data from a 2D Particle Image Velocimetry (PIV) flow analysis performed during the design of the reactor. Using different operating speeds—70, 90, 110 and 130 rpm, the flow fields were computed numerically followed by a comprehensive data analysis. The simulation results showed separated boundary layers on the rotating disc and the stator. The flow field within the reactor is characterized by a rotational plane circular forced vortex flow in which the streamlines are concentric circles with a rotational vortex. Overall, the results of the numerical simulation demonstrate a fairly good agreement between the CFD model and the experimental data as well as the available theoretical predictions. The swirl ratio β was found to be approximately 0.4044, 0.4038, 0.4044 and 0.4043 for operating speeds of N=70, 90, 110 and 130 rpm respectively. In terms of the spatial distribution, the turbulence intensity and kinetic energy are concentrated on the outer region of the reactor while the axial velocity showed a decreasing intensity towards the shroud. However, a comparison of the CFD and experimental predictions of the tangential velocity and the vorticity amplitude profiles shows that these parameters were under-predicted by the experimental analysis which could be attributed to some of the experimental limitations rather than the robustness of the CFD model or numerical code.

Study on Flow Field Character Around Bypass Crossover Sub in Fracturing Process of Horizontal Wells

2009 ◽  
Author(s):  
Zunce Wang ◽  
Yan Xu ◽  
Sen Li ◽  
Fengxia Lv ◽  
Wei Li
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Reverse Flow ◽  
Tangential Velocity ◽  
Horizontal Wells ◽  
Computational Method ◽  
Wall Area ◽  
Fracturing Process ◽  
Breadth Ratio ◽  
The Impact

Based on Reynolds Stress Model (RSM), numerical simulation of flow field around Bypass Crossover Sub in the fracturing process of horizontal wells is carried out by Computational Fluid Dynamics (CFD) analysis. Distribution rules of axial velocity, tangential velocity and radial velocity of fluid field in calculation region are achieved. Results show that strong vortexes and reverse flow exist at the slots on Bypass Crossover Sub, which brings the impact of the fluid on the wall at certain angle. Impacting velocity and angle at different positions of the wall are studied in detail. A Laser Doppler Anemometer (LDA) is applied to examine the flow field velocity distribution. Experimental results agree well with the numerical simulation results, which prove the validity of turbulence model and computational method. Numerical simulation is carried out at different Length-Breadth ratio of slots on the Bypass Crossover Sub. Effect of the Length-Breadth ratio on the scale of vortexes, speed distributions and flow field near the wall area is discussed. All of these will provide some reference on structural optimization and the analysis of erosion.

Three-dimensional numerical simulation of air flow and fiber dynamic in carding region in carding machine

2019 ◽  
Vol 89 (19-20) ◽  
pp. 3916-3926
Author(s):  
Shanshan He ◽  
Longdi Cheng ◽  
Wenliang Xue ◽  
Zhong Lu ◽  
Liguo Chen
Keyword(s):  
Mechanical Properties ◽  
Numerical Simulation ◽  
Finite Element ◽  
Flow Field ◽  
Axial Velocity ◽  
Three Dimensional ◽  
Tangential Velocity ◽  
Element Model ◽  
Mechanical Analysis ◽  
Field Simulation

Regular cylinder metallic card clothing has a limited carding efficiency. As a result of the limited dimensions, any measurement between the cylinder and flat area is difficult to make. In this study, an approach is first proposed to simulate the flow field and a fiber finite-element model on the moving surface of the teeth and produce a new design of misaligned-teeth card clothing, with the aim of improving the carding efficiency. A comparison is made between regular and misaligned-teeth card clothing types with respect to flow field simulation and fiber mechanical properties. The results show that the force resulting from the tangential velocity between the cylinder and flat is as great as 1.86 × 10−3 N, sufficient to pull fiber out of tufts, and that the tangential velocity (from 3880 to 2500 mm/s) plays a major role in this area, as opposed to the axial velocity (from 0 to 190 mm/s). Through this comparison, the misalignment design can result in a different tangential velocity distribution from that of traditional card clothing, which helps fibers between two lines of teeth move into neighboring lines of teeth, thereby increasing the likelihood that fibers will be carded. For fiber mechanical analysis, different air forces are loaded on fibers. This comparison shows that for fibers in the channel, the misalignment can help fibers move toward the teeth. Therefore, this misaligned-teeth card clothing is thought to prove more effective in practice.

Numerical Simulation of Flow Field and Separation Efficiency of Inclined Cut-In Double-Inlet Cyclone

2012 ◽  
Vol 184-185 ◽  
pp. 341-347
Author(s):  
Cai Jin Wu ◽  
Zheng Fei Ma ◽  
Yong Yang
Keyword(s):  
Numerical Simulation ◽  
Pressure Drop ◽  
Flow Field ◽  
Axial Velocity ◽  
Separation Efficiency ◽  
Tangential Velocity ◽  
Reynolds Stress Model ◽  
Stress Model ◽  
Three Dimension ◽  
Inclined Angle

The three-dimension flow field and the separation efficiency of the inclined cut-in double-inlet cyclone were simulated numerically with Reynolds Stress Model (RSM). Numerical results show that the flow field nonsymmetry is improved in the inclined cut-in double-inlet cyclone and the swirl in the flow field was decreased greatly compared to that in the single-inlet cyclone. With the increase of inclined angle, both the tangential velocity and the axial velocity first increase and then decrease, reaching a peak at inclined 12 ° angle and at inclined 10 ° angle, respectively. The pressure drop in the inclined cut-in double-inlet cyclone increases first and then decreases with the increase of inclined angle, reaching a maximum far lower than that in the single-inlet cyclone, while the change of the radial velocity is not obvious. The separation efficiency of the inclined cut-in double-inlet cyclone could be effectively improved and the optimum inclined angle is 10 °.

Numerical Analysis of the Vortex Flow Field in Cyclone Dust Collector

2013 ◽  
Vol 444-445 ◽  
pp. 524-528
Author(s):  
Peng Cheng Li ◽  
Bang Cheng Yang
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Dissipation Rate ◽  
Vortex Flow ◽  
Tangential Velocity ◽  
Dust Collector ◽  
Turbulent Dissipation ◽  
Cyclone Dust Collector ◽  
Calculation Results ◽  
Order Of Magnitude

This paper presents numerical simulation of the vortex flow field with anisotropy turbulence in cyclone dust collector using modified K-ε model and IMPLE algorithm. The axial, radial, tangential velocity field, turbulence kinetic energy K field and turbulent dissipation rate ε field were analyzed in this paper. The calculation results on the order of magnitude and the trend are agreement with the experimental results. The results show that the modified K-ε model for calculating the anisotropy turbulence is suitable.

The Comparison with Numerical Simulation Results of Steam-Water Flow Field and Experimental Data for Car Exhaust Pipe

2011 ◽  
Vol 187 ◽  
pp. 570-574
Author(s):  
Qing Guo Liu ◽  
Yan Ma ◽  
Chun Mei Yang
Keyword(s):  
Experimental Data ◽  
Numerical Simulation ◽  
Flow Field ◽  
Separation Efficiency ◽  
Tangential Velocity ◽  
Exhaust Pipe ◽  
Two Phase ◽  
Car Exhaust ◽  
Simulation Results ◽  
The Relationship

In this paper, the physical model for flow field of exhaust pipe has been established on the condition of a liquid-gas exhaust pipe from cars using ethanol gasoline. The numerical simulation results for internal flow field of car exhaust pipe are compared with the experimental data. It is showed that the outside free vortex tangential velocity and axial velocity of single-phase flow field have been simulated better. It is indicated in the simulation of separation process of steam-water two-phase: The relative error, comparing the relationship between flow and separation efficiency with measured of that is less than 7%, and the same to 15%, comparing the relationship between flow and separation ratio with measured of that. Thereby, it is confirmed correctly for the mathematical model founded for numerical calculation and the algorithm selected.

Sign in / Sign up

Export Citation Format

Share Document