Numerical Simulation on Effective Influence Radius of Hydraulic Flushing Borehole

2012 ◽  
Vol 616-618 ◽  
pp. 1021-1026 ◽  
Author(s):  
Zhi Hui Wen ◽  
Jian Ping Wei ◽  
Ying Zhen Liu ◽  
Hong Tu Zhang
Keyword(s):  
Numerical Simulation ◽  
Coupling Model ◽  
Effective Radius ◽  
Coal Mass ◽  
Volume Strain ◽  
Drainage Time ◽  
Coal Roadway ◽  
Simulation Results ◽  
Influence Radius ◽  
The Relationship

In this paper, according to the mechanics balance equation, the law of conservation of mass and the relationship between parameters including coal seam permeability, porosity and volume strain, we build a gas-solid coupling model of hydraulic flushing borehole in the coal roadway floor, and use the model to investigate the relationship between ejected coal amount and effective influence radius. The numerical simulation results indicate that the effective radius of hydraulic flushing borehole increase as the drainage time and the ejected coal amount, and the effective influence radius is 5.8m when the ejected coal mass is 1t/m, which indicate the pressure release and permeability enlarging effect is remarkable.

scholarly journals Numerical Simulation of Borehole Parameters for Coal Seam Gas Pre-Drainage

2021 ◽  
Vol 39 (4) ◽  
pp. 1328-1334
Author(s):  
Xiaoyan Li ◽  
Jiyu Zheng ◽  
Jinpin Liu
Keyword(s):  
Numerical Simulation ◽  
Pressure Drop ◽  
Gas Pressure ◽  
Borehole Diameter ◽  
Gas Drainage ◽  
Drainage Time ◽  
Drainage Radius ◽  
Simulation Results ◽  
The Impact ◽  
The Relationship

Borehole parameters are quite important for gas drainage. This paper studies the impact of borehole diameter and time on gas drainage and performs numerical simulation on the distribution of gas pressure under the conditions of different borehole diameters and drainage times. The simulation results reveal that, as the borehole diameter increases, the gas drainage volume increases along with it and the gas pressure decreases, but such effect on gas drainage is limited. In terms of drainage time, the longer the drainage time, the greater the drainage impact scope. Taking a gas pressure drop of 51% as the indicator of the effective pre-drainage radius, the distance from the point with a gas pressure drop of 51% to the position of the borehole is the effective pre-drainage radius. When the pre-drainage reached the 30th, 45th, 60th, 75th, and 90th day, the effective pre-drainage radius was 1.04m, 1.29m, 1.51m, 1.68m, and 1.82m respectively. According to the numerical simulation results, the effective pre-drainage radius varies with the pre-drainage time, and the fitting analysis of the two indicates that the relationship between the two can be described by a power function.

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.

scholarly journals The Influence of the Bottom Hole of Cold Extruding Internal Thread on Thread Quality

Mechanika ◽  
2021 ◽  
Vol 27 (4) ◽  
pp. 335-341
Author(s):  
Hongling Hou ◽  
Xin CHEN ◽  
Yongqiang ZHAO ◽  
Yayin HE ◽  
Changqian WANG
Keyword(s):  
Numerical Simulation ◽  
Extrusion Process ◽  
High Rate ◽  
Cold Extrusion ◽  
Internal Thread ◽  
Important Indicator ◽  
Good Surface ◽  
Bottom Hole ◽  
Simulation Results ◽  
The Relationship

The diameter of the threaded bottom hole determines whether the extrusion can proceed smoothly and the fullness of the tooth shape after extrusion. The tooth height rate is an important indicator of the strength of the threaded connection. In order to establish the relationship between the diameter of the bottom hole and the tooth height of the extruded internal thread, this paper takes the aluminum alloy M8×1.25 mm internal thread as an example, and uses a method of combining numerical simulation and process test. Obtained the changing law of internal thread profile and tooth height rate of extruded workpieces with different bottom hole diameters. Using MATLAB to fit the numerical simulation results, the relationship between the tooth height of the internal thread and the diameter of the prefabricated bottom hole of the workpiece was obtained. The reliability of the numerical simulation results and the feasibility of the fitting formula are verified through experiments. The results show that the diameter of the prefabricated bottom hole of the workpiece is controlled within 7.33~7.39 mm when the M8×1.25 mm internal thread is processed by the cold extrusion process. The high rate of the internal thread after extrusion meets the requirements of thread connection strength, and the internal thread has high forming quality and good surface quality.

Simulation and Experimental Study on the Impact of Breadth of Back Blade on Axial Force Balance

2011 ◽  
Vol 130-134 ◽  
pp. 1568-1572
Author(s):  
Hui Wang ◽  
Jie Gang Mu ◽  
Miao Yin Su ◽  
Shui Hua Zheng ◽  
Jin Jing Zhao ◽  
...  
Keyword(s):  
Experimental Data ◽  
Numerical Simulation ◽  
Experimental Study ◽  
Axial Force ◽  
Three Dimensional ◽  
Force Balance ◽  
Simulation And Experiment ◽  
Simulation Results ◽  
The Impact ◽  
The Relationship

The paper studies the relationship between axial force and breadth of back blade by numerical simulation and experiment. On the basis of the RNG k-ε turbulence model and technology of compact local grids and regional computing, three dimensional numerical simulations to 100HZ165-250 centrifugal pump with various breadths were carried out. Through comparing and analyzing of the flow field, it can be seen that the axial force reduces with the increase of the back blade breadth. After that, the simulation results were verified by the experimental data got from different test devices, and it shows that the conclusions are reliable.

The Numerical Simulation of Air-Cooled Plate-Fin Heat Exchanger

2011 ◽  
Vol 314-316 ◽  
pp. 1472-1477 ◽  
Author(s):  
Xue Jiang ◽  
Ji Hua Bao ◽  
Yan Yu ◽  
Ming Xia Gu
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Heat Exchanger ◽  
3D Model ◽  
Fluid Velocity ◽  
Heat Transfer Characteristics ◽  
Flow And Heat Transfer ◽  
Simulation Results ◽  
Relationship Of ◽  
The Relationship

According to the periodic structure of the plate-fin heat exchanger, 3D model of the heat exchanger is established which simplifies the computation amount of the numerical simulation on flow field and temperature field. The relationship of fluid velocity, temperature, pressure drop and heat transfer coefficient is analyzed. The flow and heat transfer characteristics can be well predicted. Based on the simulation results, the conclusion makes reference to the design of plate-fin heat exchanger.

Research on the Size Effect of Specific Cutting Energy Based on Numerical Simulation of Single Grit Scratching

2018 ◽  
Vol 140 (7) ◽  
Author(s):  
Tao Zhang ◽  
Feng Jiang ◽  
Lan Yan ◽  
Xipeng Xu
Keyword(s):  
Numerical Simulation ◽  
Size Effect ◽  
Material Removal Rate ◽  
Material Removal ◽  
Removal Rate ◽  
Specific Cutting Energy ◽  
Cutting Energy ◽  
Simulation Results ◽  
The Relationship ◽  
Single Grit Scratch

A method of research on the size effect of the specific cutting energy based on the numerical simulation has been proposed. The theoretical model of the research on size effect of specific cutting energy using single grit scratching simulation has been presented. A series of single grit scratch simulations with different scratching depths have been carried out to acquire different material removal rates. Then, the specific cutting energy has been calculated based on the power consumed and the material removal rate. The relationship between the specific cutting energy and the material removal rate has been given which agrees well with that presented by Malkin. The simulation results have been analyzed further to explain the size effect of specific cutting energy.

scholarly journals Research on the Effective Influence Radius of Hydraulic Reaming in Mining Seam

2015 ◽  
Vol 8 (1) ◽  
pp. 161-167
Author(s):  
Li Peng ◽  
Wang Kai ◽  
Li Bo ◽  
Jiang Yifeng ◽  
Gou Jianqiang
Keyword(s):  
Gas Flow ◽  
Coupling Model ◽  
Field Investigation ◽  
Coal Mass ◽  
Gas Content ◽  
Coal Seams ◽  
Gas Drainage ◽  
Permeability Increase ◽  
Influence Radius ◽  
Drainage Effect

In Accordance with the present situations suggesting that the construction of the gas drainage boreholes in mining seam is sufficient and the gas drainage effect in low permeability coal seams does not yield perfectly, the hydraulic reaming technology in mining seam was proposed to increase the gas drainage efficiency. Through the gas flow method, the effective influence radius of hydraulic reaming was determined and the fluid-solid coupling model of gas drainage along boreholes after hydraulic reaming was established theoretically. Following this, the changes in the laws of gas content around the boreholes in the coal seam were simulated and analyzed. The results indicated that hydraulic reaming can effectively promote the stress-relief and permeability-increase of the coal mass around the boreholes, and the coal mass around the reaming boreholes can be divided into gas flow increase zone, gas flow delay attenuation zone and fast decay zone. The effective influence radius of hydraulic reaming was 5.5~6 m. The obtained simulation results were basically in accordance with the field investigation.

Numerical Simulation of 6061 Aluminum Alloys during the Semi-Solid Backward Extrusion

2011 ◽  
Vol 52-54 ◽  
pp. 1532-1537
Author(s):  
Shu Zhen Shang ◽  
Gui Min Lu ◽  
Xiao Ling Tang ◽  
Zu Xin Zhao ◽  
Wei Cao
Keyword(s):  
Experimental Data ◽  
Numerical Simulation ◽  
Deformation Behavior ◽  
Processing Parameters ◽  
Stress And Strain ◽  
Backward Extrusion ◽  
Simulation Results ◽  
Semi Solid ◽  
Distribution Of Stress ◽  
The Relationship

Effects of deformation temperature and strain rate on deformation behavior of semi-solid 6061 alloy were investigated on Gleeble3800 thermal-mechanical simulator. On basis of the experimental data of semi-solid 6061, a model was established to describe the relationship between the processing parameters and flow stress, which showed that the experimental results and calculation ones fitted well. It would be beneficial to realize the distribution of stress and strain during the semi-solid forming on the basis of numerical simulation technology. This research paper presented the numerical simulation results of the 6061 alloy during the backward extrusion thixoforming process.

Solid-Gas Coupling Model and Numerical Simulation of Coal Containing Gas Based on Comsol Multiphysic

2012 ◽  
Vol 616-618 ◽  
pp. 515-520
Author(s):  
Sheng Zhou Li ◽  
Chang Bao Jiang ◽  
Jun Wei Yao ◽  
Ming Hui Li
Keyword(s):  
Numerical Simulation ◽  
Failure Modes ◽  
Coupling Effect ◽  
Coupling Model ◽  
Klinkenberg Effect ◽  
Deformation And Failure ◽  
Finite Element Software ◽  
Porosity And Permeability ◽  
Simulation Results ◽  
Seepage Law

Solid-gas coupling effect of coal containing gas is studied in order to understand the gas percolation mechanism in coal and rock. On the premise of that porosity and permeability of coal and rock are in dynamic changes and Klinkenberg effect, then seepage mechanics and elastic-plastic mechanics are considered together to established solid-gas coupling model of coal containing gas. With the given fixed solution conditions and parameters, the simulation results of mathematical model is found by the Comsol Multiphysic finite element software. Simulation results are consistent with the stress-strain law, deformation and failure modes of specimen in the experiment. Seepage law obtained in numerical simulation has same trends with experimental data. The elastoplastic solid-gas coupling model of coal containing gas can effectively describe the mechanical percolation characteristics of coal containing gas.

Effects of Mesh Size and Target Dimension on Numerical Simulation of Shaped Charge Liner Penetration into Target

2011 ◽  
Vol 52-54 ◽  
pp. 162-167 ◽  
Author(s):  
Qin Shu Miao ◽  
Xiao Ming Wang ◽  
Yu Zheng
Keyword(s):  
Numerical Simulation ◽  
Penetration Depth ◽  
Mesh Size ◽  
Critical Dimension ◽  
Shaped Charge ◽  
Test Results ◽  
Calculation Time ◽  
Target Dimension ◽  
Simulation Results ◽  
The Relationship

In order to solve two problems when simulating the phenomenon of Shaped Charge Liner penetrating into target, an example was simulated to study the influence of mesh size and target dimension on the penetration results using AUTODYN-2D. The relationship between the Shaped Charge Liner parameters and the critical dimension of the target was gained．The effects of mesh sizes on the penetration depth, aperture，and calculation time were studied. After analyzing the simulation results，a proper range of mesh size was obtained. The simulation results agree well with the test results. The research could provide reference on the simulation of Shaped Charge Liner.

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