scholarly journals Parameter optimization of anti crystallization flocking drainage pipe based on flow field distribution characteristics

2021 ◽  
Vol 25 (6 Part A) ◽  
pp. 4091-4098
Author(s):  
Shiyang Liu ◽  
Kun Xiang ◽  
Feng Gao ◽  
Xuefu Zhang ◽  
Yun Li ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Velocity Distribution ◽  
Flow Velocity ◽  
Field Distribution ◽  
Parameter Optimization ◽  
Theoretical Basis ◽  
Longitudinal Direction ◽  
Distribution Characteristics ◽  
Drainage Pipe

The crystal plugging of tunnel drainage pipe seriously affects the safe and normal use of the tunnel. In order to obtain the mechanism of flocking drainage pipe anti crystal plugging based on the characteristics of flow field distribution, numerical simulation was used to optimize the parameters of flocking drainage pipe. The results show that: with the existence of fluff, the velocity in the lower part of the drainage pipe decreases by about 50%, and the velocity in the upper part increases by about 25~50%. With the increase of the length of fluff, the velocity funnel between fluffs gradually increases, the velocity distribution at the bottom of the funnel is basically unchanged, and the velocity in the upper part gradually increases. The velocity in the upper part of the flocked drainage pipe fluctuates above the fluff to a certain extent. The flow velocity in the lower part of the drainage pipe forms a flow velocity ladder in the longitudinal direction of the villus, and the width of the ladder is about 2/3 of the longitudinal spacing of the villus. The optimized parameters of 3-D flow field of flocked drainage pipe are helpful to the further improvement of indoor test, and provide theoretical basis for the mechanism of preventing crystal blockage of flocked drainage pipe.

Numerical Simulation of Impacts of Different Types of Air Duct Outlets on Ventilation Efficiency

2013 ◽  
Vol 438-439 ◽  
pp. 1098-1103
Author(s):  
Chun Zi Nan ◽  
Ji Ming Ma ◽  
Luo Zhao
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Velocity Distribution ◽  
Flow Velocity ◽  
Numerical Method ◽  
Concentration Effect ◽  
Mixing Zone ◽  
Mixing Effect ◽  
Ventilation Efficiency ◽  
Different Types

To enhance the exhaust efficiency during ventilation, three types of air duct outlets were imported. According to the characteristics of velocity distribution simulated by numerical method, the flow field is divided into the mixing zone and the exhaust zone. The gradual contracted air duct outlet can enhance the mixing effect between fresh air and smoke. In the exhaust zone, however, the flow velocity on the upper section of the tunnel is weakened, which is unfavorable for smoke exhaust. Gradual expanded air duct outlet, on the contrary, may weaken the concentration effect of the airflow. The flow velocity on the upper section of the tunnel is increased in the exhaust zone, thus the flow field is more homogenized, which is in favor of smoke exhaust.

scholarly journals Influence of the Impeller Diameter and Off-Bottom Clearance on the Flow Velocity Distribution Characteristics Near the Bottom inside a Flotation Machine

Minerals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 31
Author(s):  
Shuling Gao ◽  
Lingguo Meng ◽  
Dezhou Wei ◽  
Qiang Zhao ◽  
Xuetao Wang ◽  
...  
Keyword(s):  
Flow Field ◽  
Velocity Distribution ◽  
Flow Velocity ◽  
Solid Particles ◽  
Distribution Area ◽  
Distribution Characteristics ◽  
Low Velocity ◽  
Flotation Machine ◽  
Design And Optimization ◽  
Velocity Magnitude

The solid particle suspension inside a flotation machine is significantly dependent on the flow field, particularly the flow hydrodynamics characteristics near the bottom of the flotation machine. In this study, a laser Doppler anemometer (LDA) was utilized to investigate the influence of the impeller diameter and the impeller off-bottom clearance of a flotation machine on the flow velocity distribution characteristics near its bottom. The results showed that centripetal, centrifugal, and transitional spiral ascending vortexes were generated for different cases of the impeller variables. The impeller diameter and the off-bottom clearance were found to have a significant and interactive influence on the flow pattern, radial and axial velocities, velocity vector distribution, and axial fluctuating root mean square (RMS) velocity characteristics. When the centripetal flow was generated with a large impeller diameter and a small off-bottom clearance, the vortex stability was improved, the low-velocity distribution area was reduced near the bottom center, and the high axial RMS velocity distribution area was extended and became more consistent. The latter provided an advantageous condition for the momentum transfer between the liquid flow and the solid particles, as well as the airflow. However, the axial RMS velocity in the centrifugal flow formed in other cases of the impeller variables was less than that in the centripetal flow. Although the increase in the impeller off-bottom clearance contributed to increasing the velocity magnitude, this is certainly disadvantageous to the service life of the impeller blades, as expected from the high-velocity area extension. These results may provide a reference for the impeller design and optimization of a KYF (Kuang Yuan Flotation) flotation machine, as well as a basis for further investigation on the behavior of the dispersed phases inside a flow field.

Flow Field Research on an M-Beam Separator

2013 ◽  
Vol 419 ◽  
pp. 165-170
Author(s):  
Yi Gang Luan ◽  
Na Liu ◽  
Zheng Wei Ma ◽  
Zheng Heng Zhao ◽  
Xiao Meng Pei
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Field Distribution ◽  
Theoretical Basis ◽  
Field Research ◽  
Resistance Characteristic ◽  
Silk Thread ◽  
2D Simulation ◽  
Display Technology ◽  
2D Numerical Simulation

The paper focuses on the resistance characteristic of a novel M-beam separator. Adopting the combination of experiment study and numerical simulation, we achieve that 2D simulation has the similar results as 3D in predicting resistance characteristic which provides the theoretical basis for next research. An M-beam separator model ten times larger than original one based on similitude principle was made for sake of flow field visualization research. The paper analyses flow field distribution of the amplifying M-beam separator by silk thread display technology and the experiment results are well consistent with 2D numerical simulation. The flow field distribution described here could serve as a reference for developing M-beam separator.

scholarly journals Two-dimensional flow field distribution characteristics of flocking drainage pipes in tunnel

Open Physics ◽  
2020 ◽  
Vol 18 (1) ◽  
pp. 139-148
Author(s):  
Shiyang Liu ◽  
Xuefu Zhang ◽  
Feng Gao ◽  
Liangwen Wei ◽  
Qiang Liu ◽  
...  
Keyword(s):  
Flow Field ◽  
Field Distribution ◽  
Rapid Development ◽  
Maximum Velocity ◽  
Distribution Characteristics ◽  
Two Dimensional ◽  
Dimensional Flow ◽  
Laboratory Test Results ◽  
Transverse Distance ◽  
Two Dimensional Flow

AbstractWith the rapid development of traffic infrastructure in China, the problem of crystal plugging of tunnel drainage pipes becomes increasingly salient. In order to build a mechanism that is resilient to the crystal plugging of flocking drainage pipes, the present study used the numerical simulation to analyze the two-dimensional flow field distribution characteristics of flocking drainage pipes under different flocking spacings. Then, the results were compared with the laboratory test results. According to the results, the maximum velocity distribution in the flow field of flocking drainage pipes is closely related to the transverse distance h of the fluff, while the longitudinal distance h of the fluff causes little effect; when the transverse distance h of the fluff is less than 6.25D (D refers to the diameter of the fluff), the velocity between the adjacent transverse fluffs will be increased by more than 10%. Moreover, the velocity of the upstream and downstream fluffs will be decreased by 90% compared with that of the inlet; the crystal distribution can be more obvious in the place with larger velocity while it is less at the lower flow rate. The results can provide theoretical support for building a mechanism to deal with and remove the crystallization of flocking drainage pipes.

Numerical Simulation of Condenser Throat Combining with Low-Pressure Exhaust Hood for 600MW Thermal Power Unit

2012 ◽  
Vol 614-615 ◽  
pp. 77-82
Author(s):  
Jian Li ◽  
Li Zhang ◽  
Si Ping Wang
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Velocity Distribution ◽  
Calculation Result ◽  
Thermal Power ◽  
Low Pressure ◽  
Exhaust Hood ◽  
Combined Model ◽  
Real Condition ◽  
Reasonable Result

In order to obtain the more real condition of the flow field at condenser throat the flow field of condenser throat is numerical simulated by the FLUENT commercial software, alone or coupling with the low-pressure exhaust hood. The results show that the flow field of condenser throat is strongly influenced by low-pressure exhaust hood, the frustum’s diffuse-angle, the low-pressure heater and the injection of the exhaust steam from the small turbine. The velocity distribution at the outlet of the throat isn’t uniform. The calculation result of combined model is also different from the single calculation result of condenser throat. Combined numerical simulation obtains more reasonable result.

Flow Field Analysis of Conducting Trunk of Comb-Type Cotton Picker

2012 ◽  
Vol 468-471 ◽  
pp. 1749-1752
Author(s):  
Chun Yao Wang ◽  
Xue Nong Wang ◽  
Fa Chen ◽  
Yue Liu ◽  
Jiu Peng Chi ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Velocity Field ◽  
Flow Field ◽  
Field Analysis ◽  
Distribution Characteristics ◽  
Pneumatic Conveying ◽  
Simulation Research ◽  
Cotton Picker ◽  
Different Types ◽  
Flow Field Analysis

This article uses the flow field numerical simulation technology, it does simulation research for the flow field of the whole pneumatic conveying cotton trunk, through studying different types of jet orifice of the conveying trunk of comb—type cotton picker, finding out the influence of jet orifice width on pressure and velocity field, further understanding flow field distribution characteristics of the internal pneumatic cotton conveyance system, and providing necessary basis for the machine.

Research on the Relationship of Flow Velocity and Particles’ Separation in Cyclone

2012 ◽  
Vol 479-481 ◽  
pp. 2529-2532
Author(s):  
Ying Zhang ◽  
Zhen Wei Zhang
Keyword(s):  
Numerical Simulation ◽  
Velocity Distribution ◽  
Flow Velocity ◽  
Structure Design ◽  
Rotating Flow ◽  
Separation Performance ◽  
Simulation Results ◽  
Relationship Of ◽  
The Relationship ◽  
Distribution Of Flow

This paper mainly focuses on the numerical simulation of flow velocity aiming to obtain the velocity distribution of flow in the cyclone. The authors took advantage of RSM turbulence model of software FLUENT to calculate the velocity distribution. Relationship between particles separation and double-layer rotating flow can be obtained based on the simulation results, which can also provide basis for the improvement of structure design and separation performance.

Numerical Simulation of the Flow Field in Safety Valve

2012 ◽  
Vol 472-475 ◽  
pp. 1432-1436
Author(s):  
Xiao Bin Ji ◽  
Xue Yi Qi ◽  
Xiao Yan Li ◽  
Wan Bin Jin
Keyword(s):  
Fluid Dynamics ◽  
Numerical Simulation ◽  
Computational Fluid Dynamics ◽  
Reynolds Number ◽  
Flow Field ◽  
Field Distribution ◽  
Safety Valve ◽  
Structural Parameters ◽  
Flow Noise ◽  
Simulating Calculation

By using the Reynolds stress turbulence model at big Reynolds number condition and computational fluid dynamics, the data simulating calculation was carried out to the safety valve inner flow field with different opening size and different valve structural parameters. The result were showed in visual graphics , and the study showed that the valve structural parameters impact on the flow field distribution , the cavitation creation and the flow noise greatly.

Numerical Simulation of Pulse Cleaning Process in Ceramic Filtration System

2013 ◽  
Vol 726-731 ◽  
pp. 2220-2223
Author(s):  
Hai Xia Li ◽  
Wei Jiang
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Simulation Model ◽  
Field Distribution ◽  
Pressure Variation ◽  
Lower Pressure ◽  
Cleaning Process ◽  
Filtration System ◽  
Nozzle Shape ◽  
Ceramic Filtration

The numerical simulation model was established using FLUENT code to analysis the flow field of pulse cleaning process of filtration system. The pressure variation with pulse cleaning time was studied. The effect of nozzle shape and diffuser shape on flow field was investigated. The diffuser construct can affect the flow field distribution, but the effect is little. The converged nozzle can bring better pulse cleaning effect by bring higher velocity and lower pressure at outlet.

scholarly journals Numerical Simulation Research on Distribution Characteristics of Overlying Rock Stress Field in Floor Roadway

2021 ◽  
Vol 257 ◽  
pp. 03024
Author(s):  
Zhonghua Wang
Keyword(s):  
Stress Field ◽  
Field Distribution ◽  
Theoretical Basis ◽  
Surrounding Rock ◽  
Horizontal Distance ◽  
Distribution Characteristics ◽  
Rock Stress ◽  
Simulation Research ◽  
Location Selection ◽  
Coal Roadway

In order to explore the distribution characteristics of the overlying rock stress field in the floor roadway at different locations, FLAC3D software was used to simulate and analyze the surrounding rock directly above the floor roadway and the surrounding rock within 15m on both sides of the floor roadway when the distance between the floor roadway and the coal roadway and the horizontal distance were changed. The stress field distribution characteristics are obtained, and the stress field distribution characteristics of different areas directly above and on both sides of the floor roadway are obtained, which provides a theoretical basis for the location selection and support of the floor roadway.

Sign in / Sign up

Export Citation Format

Share Document