scholarly journals Experimental Study on Flow Characteristics of Aeolian Sand in Fractures

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Jiarui Chen ◽  
Wenhu Gu ◽  
Jihua Zhang ◽  
Jitao Tang ◽  
Zhengzheng Cao ◽  
...  
Keyword(s):  
Experimental Study ◽  
Research Work ◽  
Flow Characteristics ◽  
Test System ◽  
Western China ◽  
Aeolian Sand ◽  
Fracture Angle ◽  
Working Face ◽  
Fracture Opening ◽  
Dip Angle

It is one of the important safety problems in the process of mining shallow coal seams in western China that the rock mass affected by mining stress breaks and forms a penetrating fracture, leading to a sand burst in the working face. The self-developed test system is used to carry out the experimental study on the flow characteristics of Aeolian sand in fractures. The research work is focused on the influence of several parameters, such as the thickness of the Aeolian sand layer, the fracture opening, and the fracture dip angle on the velocity of sand particles in fractures. The results show the following: (1) The influence of fracture opening and fracture angle on sand burst rate is much greater than that of sand thickness. No matter what the fracture angle and fracture opening value are, the influence weight of sand thickness on sand burst rate is almost zero. (2) When other conditions are unchanged, with the increase of fracture dip angle, the sand burst rate increases significantly, and the relationship between the sand burst rate and the fracture dip angle is exponential. (3) The influence weight of fracture opening is the largest. With the increase of fracture opening, the sand burst rate increases logarithmically. Finally, according to the test results, the relation equation which can simultaneously describe the influence of fracture opening and fracture inclination on the rate of the sand burst is fitted. This study can provide a theoretical basis and scientific guidance for the prevention and control of coal mine sand inrush disasters caused by roof cracking in western coal mines.

scholarly journals Experimental study on the mean flow characteristics of a supersonic multiple jet configuration

2021 ◽  
Vol 108 ◽  
pp. 106377
Author(s):  
Mohammed Faheem ◽  
Aqib Khan ◽  
Rakesh Kumar ◽  
Sher Afghan Khan ◽  
Waqar Asrar ◽  
...  
Keyword(s):  
Experimental Study ◽  
Flow Characteristics ◽  
Mean Flow ◽  
The Mean

Experimental study of the effects of air volume ratios on the air curtain dust cleaning in fully mechanized working face

2021 ◽  
Vol 293 ◽  
pp. 126109
Author(s):  
Hao Wang ◽  
Weimin Cheng ◽  
Zhanyou Sa ◽  
Jie Liu ◽  
Ran Zhang ◽  
...  
Keyword(s):  
Experimental Study ◽  
Air Curtain ◽  
Air Volume ◽  
Working Face

An experimental study on the flow characteristics during the leakage of high pressure CO2 pipelines

2019 ◽  
Vol 125 ◽  
pp. 92-101 ◽  
Author(s):  
Shuaiwei Gu ◽  
Yuxing Li ◽  
Lin Teng ◽  
Cailin Wang ◽  
Qihui Hu ◽  
...  
Keyword(s):  
Experimental Study ◽  
High Pressure ◽  
Flow Characteristics ◽  
High Pressure Co2

Experimental study of the helium flow characteristics in pebble-bed under the condition of CFETR's blanket module

2017 ◽  
Vol 100 ◽  
pp. 283-291 ◽  
Author(s):  
Mingjun Wang ◽  
Di Liu ◽  
Yan Xiang ◽  
Shijie Cui ◽  
G.H. Su ◽  
...  
Keyword(s):  
Experimental Study ◽  
Flow Characteristics ◽  
Helium Flow ◽  
Pebble Bed

scholarly journals Flow Characteristics and Grain Size Distribution of Granular Gangue Mineral by Compaction Treatment

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Ran Yuan ◽  
Dan Ma ◽  
Hongwei Zhang
Keyword(s):  
Weight Loss ◽  
Grain Size ◽  
Size Distribution ◽  
Grain Size Distribution ◽  
Water Flow ◽  
Fine Particles ◽  
Flow Characteristics ◽  
Test System ◽  
Chemical Components ◽  
Gangue Mineral

A test system for water flow in granular gangue mineral was designed to study the flow characteristics by compaction treatment. With the increase of the compaction displacement, the porosity decreases and void in granular gangue becomes less. The main reason causing initial porosity decrease is that the void of larger size is filled with small particles. Permeability tends to decrease and non-Darcy flow factor increases under the compaction treatment. The change trend of flow characteristics shows twists and turns, which indicate that flow characteristics of granular gangue mineral are related to compaction level, grain size distribution, crushing, and fracture structure. During compaction, larger particles are crushed, which in turn causes the weight of smaller particles to increase, and water flow induces fine particles to migrate (weight loss); meanwhile, a sample with more weight of size (0–2.5 mm) has a higher amount of weight loss. Water seepage will cause the decrease of some chemical components, where SiO2 decreased the highest in these components; the components decreased are more likely locked at fragments rather than the defect of the minerals. The variation of the chemical components has an opposite trend when compared with permeability.

Experimental study of the flow characteristics in a falling film liquid desiccant dehumidifier

2016 ◽  
Vol 23 (1) ◽  
pp. 157-165 ◽  
Author(s):  
Yimo Luo ◽  
Yi Chen ◽  
Dan Zhong ◽  
Yuanhao Wang ◽  
Hongxing Yang
Keyword(s):  
Experimental Study ◽  
Flow Characteristics ◽  
Falling Film ◽  
Liquid Desiccant

Numerical Study on Flow Characteristics in High Multi-Stage Pressure Reducing Valve

2017 ◽  
Author(s):  
Fu-qiang Chen ◽  
Zhi-xin Gao ◽  
Jin-yuan Qian ◽  
Zhi-jiang Jin
Keyword(s):  
Energy Consumption ◽  
Numerical Study ◽  
Research Work ◽  
Flow Characteristics ◽  
Temperature Fields ◽  
Turbulent Dissipation ◽  
Technological Support ◽  
Multi Stage ◽  
Valve Opening ◽  
Pressure Reducing Valve

In this paper, a new high multi-stage pressure reducing valve (HMSPRV) is proposed. The main advantages include reducing noise and vibration, reducing energy consumption and dealing with complex conditions. As a new high pressure reducing valve, its flow characteristics need to be investigated. For that the valve opening has a great effect on steam flow, pressure reduction and energy consumption, thus different valve openings are taken as the research points to investigate the flow characteristics. The analysis is conducted from four aspects: pressure, velocity, temperature fields and energy consumption. The results show that valve opening has a great effect on flow characteristics. No matter for pressure, velocity or temperature field, the changing gradient mainly reflects at those throttling components for all valve openings. For energy consumption, in the study of turbulent dissipation rate, it can be found that the larger of valve opening, the larger of energy consumption. It can be concluded that the new high multi-stage pressure reducing valve works well under complex conditions. This study can provide technological support for achieving pressure regulation, and benefit the further research work on energy saving and multi-stage design of pressure reducing devices.

Experimental study of gas-liquid-solid flow characteristics in slurry Taylor flow-based multiphase microreactors

2021 ◽  
Vol 405 ◽  
pp. 126646
Author(s):  
Zhengbiao Peng ◽  
Shaolei Gai ◽  
Milan Barma ◽  
Mohd. Mostafizur Rahman ◽  
Behdad Moghtaderi ◽  
...  
Keyword(s):  
Experimental Study ◽  
Flow Characteristics ◽  
Solid Flow ◽  
Taylor Flow

scholarly journals Study on Fracture and Stress Evolution Characteristics of Ultra-Thick Hard Sandstone Roof in the Fully Mechanized Mining Face with Large Mining Height: A Case Study of Xiaojihan Coal Mine in Western China

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Feng Ju ◽  
Meng Xiao ◽  
Zequan He ◽  
Pai Ning ◽  
Peng Huang
Keyword(s):  
High Strength ◽  
Western China ◽  
Stress Evolution ◽  
Working Face ◽  
Mining Condition ◽  
Evolution Characteristics ◽  
Large Mining Height ◽  
Evolution Laws ◽  
Mining Face ◽  
Mining Height

Ultra-thick hard sandstone roofs present high thickness, poor delamination, and wide caving range. The strata pressure of the working face during actual mining increases, having a significant influence on the safe mining of the working face. Especially, in the mining areas of western China, the fully mechanized mining faces with high mining height and high-strength mining are more prominent. Understanding the fractures and stress evolution characteristics of the ultra-thick hard sandstone roof during actual mining is of high significance to control the dynamic pressure on the working face. In this paper, the typical ultra-thick hard sandstone roof of the Xiaojihan coal mine was taken as an example. The structural and chemical composition characteristics were analyzed. Besides, the fracture characteristics of ultra-thick hard roof during the working face mining were analyzed. Moreover, the fracture structure consistency was verified through physical simulation and a field measurement method. Finally, the stress evolution laws in the ultra-thick hard sandstone roof fracture were studied through numerical simulation. The findings demonstrated that (1) the ultra-thick hard sandstone roof was composed of inlaid coarse minerals, which had compact structure, while the Protodyakonov hardness reached up to 3.07; (2) under the high-strength mining condition of fully mechanized mining face with large mining height, the ultra-thick hard sandstone roof had the characteristics of brittle fracture, with a caving span of 12 m; (3) under the high-strength mining condition of fully mechanized mining face with large mining height, the ultra-thick hard sandstone roof followed the stress evolution laws that were more sensitive to the neighboring goaf. Therefore, it was necessary to reduce the fracture span or layering of ultra-thick hard sandstone roof through the manual intervention method adoption or increase either the strength of coal pillar or supporting body, to resist the impact generated during ultra-thick hard sandstone roof fracture.

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