Simulation analysis and engineering application of distribution characteristics about multi-stage atomization field for cutting dust in fully mechanized mining face

2019 ◽  
Vol 30 (11) ◽  
pp. 2600-2615 ◽  
Author(s):  
Wenjing Yin ◽  
Gang Zhou ◽  
Danhong Gao
2021 ◽  
Author(s):  
Lili Zheng ◽  
Zheng Gao

The old mining area in Pingdingshan coalfield has the following problems: long mining service life, many remaining coal pillars, and great difficulty in mining; to extend the service life of the mine, realize cost saving and efficiency increasing, it is urgent to recover the remaining coal pillars, but the mining of isolated island face faces the problem of reasonable retention of waterproof coal pillars, if the protection is not good, it is easy to cause mine water damage and increase the mining cost. Therefore, in view of the practical engineering problems faced by the field, aiming at eliminating or reducing the goaf water disaster, this paper adopts numerical simulation research methods to optimize the original design scheme and carry out comparative analysis, dynamically reappear the surrounding rock stress field, displacement field and plastic failure law under multi face mining and roadway mining, and carry out engineering practice application. The results show that there is a certain thickness of elastic core area before and after mining with 25m coal pillar width. The deformation of surrounding rock is small, which is conducive to roadway maintenance, without obvious stress concentration. It can meet the actual needs of the project. The mining face has achieved safe mining, without water inrush accident in the goaf, and the coal resources have been recovered to the maximum extent. The research results are left over to similar mining areas in China The safe recovery of coal pillar can be used for reference.


2018 ◽  
Vol 185 ◽  
pp. 00002
Author(s):  
Shih-Hsien Lin ◽  
Un-Chin Chai ◽  
Gow-Yi Tzou ◽  
Dyi-Cheng Chen

Three are generalized simulation optimizations considering the forging force, the die stress, and the dual-goals in two-stage forging of micro/meso copper fastener. Constant shear friction between the dies and workpiece is assumed to perform multi-stage cold forging forming simulation analysis, and the Taguchi method with the finite element simulation has been used for mold-and-dies parameters design simulation optimizations considering the forging force, die stress, and dual-goals. The die stress optimization is used to explore the effects on effective stress, effective strain, velocity field, die stress, forging force, and shape of product. The influence rank to forging process of micro/meso copper fastener for three optimizations can be determined, and the optimal parameters assembly consider die stress can be obtained in this study. It is noted that the punch design innovation can reduce the forging force and die stress.


2020 ◽  
Vol 74 (5) ◽  
pp. 583-596
Author(s):  
Xingjia Tang ◽  
Zongben Xu ◽  
Libo Li ◽  
Shuang Wang ◽  
Bingliang Hu ◽  
...  

Hadamard coding spectral imaging technology is a computational spectral imaging technology, which modulates the target’s spectral information and recovers the original spectrum by inverse transformation. Because it has the advantage of multichannel detection, it is being studied by more researchers. For the engineering realization of push-broom coding spectral imaging instrument, it will inevitably be subjected to push-broom error, template error and detection noise, the redundant sampling problem caused by detector. Therefore, three restoration methods are presented in this paper: firstly, the one is the least squares solution, the two is the zero-filling inverse solution by extending the coding matrix in the redundant coding state to a complete higher order Hadamard matrix, the three is sparse method. Secondly, the numerical and principle analysis shows that the inverse solution of zero-compensation has better robustness and is more suitable for engineering application; its conditional number, error expectation and covariance are better and more stable because it directly uses Hadamard matrix, which has good generalized orthogonality. Then, a real-time spectral reconstruction method is presented, which is based on inverse solution of zero-compensation. Finally, simulation analysis shows that spectral data could be destructed relative accuracy in the error condition; however, the effect of template noise and push error on reconstruction is much greater than that of detection error. Therefore, in addition to reducing the detection noise as much as possible, lower template noise and more accurate push controlling should be guaranteed specifically in engineering realization.


2011 ◽  
Vol 291-294 ◽  
pp. 958-963
Author(s):  
Li Jie Cao

The residual stress fields can have strong influences on the integrity and performance of friction stir welded aluminum alloy structure, comprehensive insight into the residual stress distribution is the key to the Friction stir welding (FSW) engineering application for a wide range of materials and thicknesses improving the weld strength and fatigue life. In this paper, the current state of the residual stresses in the FSW aluminum alloy joints is reviewed, The focus is on recent advances of experimental research, the results of numerical simulation analysis, and the effects of the technological parameters(welding speed, rotational speed, shoulder geometry et al.) on residual stress fields was evaluated. In the end, The controlling technique of residual stresses from published literatures is summarized.


2021 ◽  
Author(s):  
Minglin Ma ◽  
Yang Yang ◽  
Zhicheng Qiu ◽  
Yuexi Peng ◽  
Yichuang Sun ◽  
...  

Abstract The continuous memristor is a popular topic of research in recent years, however, there is rare discussion about the discrete memristor model, especially the locally active discrete memristor model. This paper proposes a locally active discrete memristor model for the first time and proves the three fingerprints characteristics of this model according to the definition of generalized memristor. A novel hyperchaotic map is constructed by coupling the discrete memristor with a two-dimensional generalized square map. The dynamical behaviors are analyzed with attractor phase diagram, bifurcation diagram, Lyapunov exponent spectrum, and dynamic behavior distribution diagram. Numerical simulation analysis shows that there is significant improvement in the hyperchaotic area, the quasi-periodic area and the chaotic complexity of the two-dimensional map when applying the locally active discrete memristor. In addition, antimonotonicity and transient chaos behaviors of system are reported. In particular, the coexisting attractors can be observed in this discrete memristive system, resulting from the different initial values of the memristor. Results of theoretical analysis are well verified with hardware experimental measurements. This paper lays a great foundation for future analysis and engineering application of the discrete memristor and relevant the study of other hyperchaotic maps.


2013 ◽  
Vol 579-580 ◽  
pp. 265-269 ◽  
Author(s):  
Yong Xiang Li ◽  
Wen Quan Shen ◽  
You Jia Zhao ◽  
Xiu Yang Hu

As to the practical problems of vibration and noise of automobile transmission, this paper focuses on the gear pair of automobile transmission as the research object to realize the gear meshing analysis with the software MASTA. Through establishing the simulation model of the automobile transmission to simulate the actual load condition, the process analysis of comprehensive intelligent gear modification is carried on. Finally, the reasonable modification results indicate that the simulation analysis recurring to the professional software can obtain the modified gear of the automobile transmission more suitable to the engineering application, which will provide good guidance for the development and application of new transmission gear in the future and lay the research foundation to reduce the vibration and noise of the transmission based on the gear modification method.


2021 ◽  
Vol 2083 (4) ◽  
pp. 042091
Author(s):  
Wei Zhang ◽  
Peigang Jiao ◽  
Qinzhong Hou

Abstract The method based on Smooth Particle Hydrodynamics (SPH) is a meshless method which is widely used at present. Its advantage is that it can effectively improve the mesh distortion when finite element is used to deal with large deformation, and its particle characteristics are suitable to deal with the simulation problem of fluid. Based on the actual vehicle wading test site and the actual parameters of the vehicle, combined with the actual situation and theoretical basis, the SPH method is used for numerical simulation analysis of the vehicle wading problem. By comparing the simulation process with the actual water changes during wading, the feasibility of using SPH method in vehicle wading application is proved. In the simulation process of vehicle wading driving, under the condition of constant water level, by setting different wading speeds of vehicle, the flow law and change mechanism of water free surface are analyzed, which are of great significance in theoretical research and engineering application research.


2020 ◽  
pp. 172-172
Author(s):  
Xudong Sun ◽  
Xiaoming Xu ◽  
Wei Tang ◽  
Huifen Jin ◽  
Hua Ding

High-speed rail vehicles need to start the emergency traction battery system in an emergency. In order to ensure that the emergency traction battery system can be quickly started in cold conditions and ensure that the high-speed railway has sufficient mileage, this paper proposes a multi-stage heating method based on flat heat pipes. The thermodynamic parameters of the power battery are obtained by simulation analysis and experimental verification. According to the thermodynamic model, the heat generation model and coupled heat transfer model of the battery are established. Different heating powers are assigned to different heating points and the total heating power is kept constant. Through the analysis results, the multi-stage heating device of the emergency traction battery system can effectively reduce the heating time under cold conditions and the temperature difference between the battery system modules. This paper can provide reference to the design of the battery pack and the matching of the heating system.


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