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.

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.

Characteristic Analysis for the Internal Flow Field of CVT Torque Converter Based on FLUENT

2013 ◽  
Vol 427-429 ◽  
pp. 29-32
Author(s):  
Jin Gang Liu ◽  
Le Xiong ◽  
Yuan Qiang Tan
Keyword(s):  
Flow Field ◽  
Velocity Distribution ◽  
Channel Model ◽  
Internal Flow ◽  
Torque Converter ◽  
Characteristic Analysis ◽  
Design And Optimization ◽  
Distribution Of Flow

According to the issue of CVT torque converter internal flow field such as the complexity and not easy to calculate, the channel model of torque converter is established by UG, the grid of channel model is generated by GAMBIT, the internal flow field of torque converter is simulated based on FLUENT while the pressure and velocity distribution of flow field are calculated under three different conditions. The results show that analyzing the flow field of torque converter by FLUENT has certain guiding significance for the design and optimization of torque converter.

Simulation on the Flow Field of Mini-Hydrocyclones for Different Inlet Sizes

2013 ◽  
Vol 864-867 ◽  
pp. 1183-1191 ◽  
Author(s):  
Chao Yan ◽  
Qiang Yang ◽  
Hua Lin Wang
Keyword(s):  
Aspect Ratio ◽  
Flow Field ◽  
Solid Particles ◽  
Design And Optimization ◽  
Fluent Software ◽  
Simulation Results ◽  
Shape And Size

This paper aims to improve the separation of fine solid particles in mini-hydrocyclones by changing the shape and size of the mini-hydrocyclone inlet. This study also examines the best mini-hydrocyclone inlet shape and size. Fluent software is used to simulate the flow field of the continuous and dispersion phases in different mini-hydrocyclone. The simulation results can guide the design and optimization of mini-hydrocyclones and determine the optimum inlet aspect ratio.

Distribusi Kecepatan dan Konsentrasi Sedimen Suspensi pada Aliran Menikung (Studi Kasus pada Saluran Irigasi Mataram Yogyakarta)

2016 ◽  
Vol 12 (1) ◽  
pp. 11
Author(s):  
Chairul Muharis
Keyword(s):  
Velocity Distribution ◽  
Flow Velocity ◽  
Suspended Sediment ◽  
Centrifugal Force ◽  
Suspended Sediment Concentration ◽  
Sediment Concentration ◽  
Low Velocity ◽  
Distribution Profile ◽  
Bend Flow ◽  
Distribution Of Flow

The flow velocity and suspended sediment concentration are important parameters of sediment transport mechanisms, especially for agradation and degradation problems. The centrifugal force at the bend channels will increased flow velocity at the outer bank of the bend. It is of course also affects the distribution of flow velocity toward the outside and the inside of the bend channels. The change of the velocity distribution  it is very possible also changes the distribution of suspended sediment concentration. In this paper will discuss the velocity distribution profile and distribution of sediment concentration in the bend flow. This research was conducted at Mataram Irrigation Channel Yogyakarta. The channel rectangular in shape and made of masonry with angle bend 580. Measuring the flow velocity used Propeller currentmeter and  sediment concentration used Opcon Probe. Measuring flow velocity and sediment concentration conducted simultaneously for each measurement point.The results showed that due to the centrifugal force in bend flow, flow velocity distribution and sediment concentration distribution undergoing significant change the outside and the inside of the bend. In general, the distribution of flow velocity toward the outerbank of the bend has increased and the distribution suspended  sediment concentration has decrease  and the opposite occurs innerbank of the bend. A low velocity on the inner bank of the channel bend causes larger grains of sediment that settles and potentially silting.

scholarly journals Research on the influence of elbow erosion characteristics based on bionic earthworm dorsal pore jet

2019 ◽  
Vol 103 (1) ◽  
pp. 003685041987423
Author(s):  
Jiegang Mou ◽  
Wenqi Zhang ◽  
Yunqing Gu ◽  
Chengqi Mou
Keyword(s):  
Flow Velocity ◽  
Erosion Rate ◽  
Lower Surface ◽  
Solid Particles ◽  
Discrete Phase Model ◽  
Low Velocity ◽  
Erosion Area ◽  
Discrete Phase ◽  
Jet Velocity ◽  
Elbow Erosion

Based on the biological characteristics of earthworm, the dorsal pore jet parameters were analyzed to establish elbow erosion model. The discrete phase model and standard k-ε turbulence model were used to carry on numerical simulation of the erosion characteristics and study the mechanism of improving elbow erosion characteristics. The results showed that the most serious erosion area was the elbow lower surface, while bionic earthworm dorsal pore jet could significantly reduce the erosion rate of this area, thereby reducing the overall erosion rate. When the jet velocity was the same, the smaller the jet distance, the lower the erosion rate would be. With the increase of the jet velocity, the erosion rate decreased first and then increased. When the jet distance was 0.5 times the elbow diameter and the jet velocity was 0.3 times the flow velocity, the erosion rate was the lowest (decreased by 79.29%). When the jet velocity was less than 0.5 m·s−1, low-velocity strips formed at elbow lower surface due to the jet and reduced the kinetic energy of the solid particles near the wall; when the jet velocity was greater than 0.2 times the flow velocity, vortex cushion effect formed, therefore reduced the erosion rate significantly.

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