scholarly journals Numerical simulation research on dynamical variation of permeability of coal around roadway based on gas-solid coupling model for gassy coal

2018 ◽  
Vol 28 (6) ◽  
pp. 925-932 ◽  
Author(s):  
Tao Yang ◽  
Bo Li ◽  
Qiusheng Ye
Keyword(s):  
Numerical Simulation ◽  
Coupling Model ◽  
Simulation Research

scholarly journals Numerical and Experimental Study of Lightning Stroke to BIPV Modules

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 748
Author(s):  
Xiaoyan Bian ◽  
Yao Zhang ◽  
Qibin Zhou ◽  
Ting Cao ◽  
Bengang Wei
Keyword(s):  
Numerical Simulation ◽  
Experimental Study ◽  
Coupling Model ◽  
Maximum Temperature ◽  
Lightning Stroke ◽  
Study Results ◽  
Pv Modules ◽  
New Type ◽  
Metal Frame ◽  
Current Flows

Building Integrated Photovoltaic (BIPV) modules are a new type of photovoltaic (PV) modules that are widely used in distributed PV stations on the roof of buildings for power generation. Due to the high installation location, BIPV modules suffer from lightning hazard greatly. In order to evaluate the risk of lightning stroke and consequent damage to BIPV modules, the studies on the lightning attachment characteristics and the lightning energy withstand capability are conducted, respectively, based on numerical and experimental methods in this paper. In the study of lightning attachment characteristics, the numerical simulation results show that it is easier for the charges to concentrate on the upper edge of the BIPV metal frame. Therefore, the electric field strength at the upper edge is enhanced to emit upward leaders and attract the lightning downward leaders. The conclusion is verified through the long-gap discharge experiment in a high voltage lab. From the experimental study of multi-discharge in the lab, it is found that the lightning interception efficiency of the BIPV module is improved by 114% compared with the traditional PV modules. In the study of lightning energy withstand capability, a thermoelectric coupling model is established. With this model, the potential, current and temperature can be calculated in the multi-physical field numerical simulation. The results show that the maximum temperature of the metal frame increases by 16.07 °C when 100 kA lightning current flows through it and does not bring any damage to the PV modules. The numerical results have a good consistency with the experimental study results obtained from the 100 kA impulse current experiment in the lab.

scholarly journals Numerical Simulation Research on Multi-field Coupling of Underground Energy Pile

2021 ◽  
Vol 1838 (1) ◽  
pp. 012061
Author(s):  
Qihui Zhou ◽  
Zhanjun Huang ◽  
Yong Wu ◽  
Huipeng Zhang ◽  
Yufeng Shi ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Simulation Research ◽  
Energy Pile ◽  
Field Coupling

Simulation Research on Control Technology of Micro-Particle Adhesion to Surface

2011 ◽  
Vol 181-182 ◽  
pp. 366-371
Author(s):  
Hui Liu ◽  
Yan Qiang Li
Keyword(s):  
Numerical Simulation ◽  
Electrostatic Force ◽  
Actual State ◽  
Control Technology ◽  
Particle Adhesion ◽  
Adhesion Mechanism ◽  
Simulation Research ◽  
Mechanical Models ◽  
Analysis Of Results ◽  
Simulation Package

The micro particle brings much harm to some industrials, agriculture and human activities. The mechanical models of micro particle adhesion to the surface and the control, disposal technology have become very important for prevention from particle aggradations. For the sake of deeply comprehending and researching the adhesion mechanism as well as kinematics characteristic, numerical simulation of particle adhesion was made based on compute simulation package, the analysis of results and relevant comparison demonstrate that it can well simulate actual state and the results of simulation show that the capillary force (Fc) is the biggest, by contrast, the electrostatic force (Fes) is the smallest. Further more, it has some valuable instructions and helpful references for control of micro-particle adhesion to surface. At last, the outlook of issue was put forward.

Numerical Simulation Research on the Shape of Top Coal Drawn-Body in Gently Inclined Seam

2012 ◽  
Vol 468-471 ◽  
pp. 2248-2254
Author(s):  
Qiang Li ◽  
Wan Kui Bu ◽  
Hui Xu ◽  
Xiao Bo Song
Keyword(s):  
Numerical Simulation ◽  
Numerical Model ◽  
Random Medium ◽  
Body Movement ◽  
The Other ◽  
Simulation Research ◽  
Research Results ◽  
Shape Equation ◽  
The Difference ◽  
Meso Scale

The numerical model of top coal drawing in gently inclined seam is built based on PFC2d software. By comparing with the theory of drawn-body movement law, it can be obtained that the shape of top coal drawn-body accords with the theory of random medium movement. The research results show that the form of the shape equation of top coal drawn-body is uniform while the top coal caving angle is different. On the other hand, with the difference of top coal caving angle and drawing height, the shape of top coal drawn-body is differential at the meso scale, which depends on the parameters of the shape equation of top coal drawn-body.

Numerical Simulation Research on Springback Controlling Methods of Aluminum Alloy Panel during Hydroforming

2016 ◽  
Vol 851 ◽  
pp. 163-167
Author(s):  
Dong Yan Lin ◽  
Yi Li
Keyword(s):  
Numerical Simulation ◽  
Aluminum Alloy ◽  
Process Parameters ◽  
Orthogonal Experiment ◽  
Blank Holder Force ◽  
Scoring Method ◽  
Simulation Research ◽  
Blank Holder ◽  
Hydroforming Process

The hydroforming process of the aluminum alloy panel was simulated by the software DYNAFORM. The effects of process parameters (blank holder force, depth of panel and height of draw bead) on springback of the aluminum alloy were investigated. The max springback of the panel was analyzed by weighted scoring method. Then the process parameters were synthetically optimized for the max positive and negative springback. The results showed that the height of draw bead affects obviously the comprehensive springback of the panel. The optimization of the process parameters obtained by the orthogonal experiment can effectively reduce the max springback of the panel.

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