Peixian Li^1,*, Zhixiang Tan², Lili Yan³

CMES-Computer Modeling in Engineering & Sciences, Vol.117, No.2, pp. 231-250, 2018, DOI:10.31614/cmes.2018.02573

Abstract In order to prolong the life cycle of the coal mine, Jinggezhuang (‘JGZ’) coal mine decided to excavate the shaft pillar. The first panel 0091 was designed near the pillar boundary as an experiment in shaft pillar mining. Both probability integral method (PIM) and FLAC^3D were used to evaluate the influence on the shaft safety. PIM parameters were obtained from previous surface subsidence station. The rock property is based on the lab mechanical test. A simulated FLAC^3D model containing shafts and a panel was built based on stratigraphic information. Surface subsidence results of PIM show that… More >

Haojun Peng^1,*, Ping Zhang²

CMES-Computer Modeling in Engineering & Sciences, Vol.114, No.1, pp. 59-73, 2018, DOI:10.3970/cmes.2018.114.059

Abstract In this paper, a three dimension model is built according to real surface cleaner in airport runway rubber mark cleaning vehicle and numerical simulation of this model is carried out using Ansys Fluent software. After comparison and analysis the flow field between high speed rotating waterjet and static waterjet formerly studied by other researchers, the influences of different standoff distance from nozzle outlet to runway surface and rotation speed on rubber mark cleaning effect is simulated and analyzed. Results show the optimal operation parameters for the simulated model and quantitative advices are given for design, More >

Yi Xue^1,2,3

CMES-Computer Modeling in Engineering & Sciences, Vol.113, No.4, pp. 429-441, 2017, DOI:10.3970/cmes.2017.113.429

Abstract The lack of research on the effect of diffusion on methane extraction leads to low methane concentration and low utilization. The Comsol Multiphysics software is used to solve the numerical gas and solid coupled model which considers the diffusion of coal matrix, fracture seepage, permeability evolution and coal deformation. The simulation results reveal the effect of diffusion process on methane migration. The gas diffusion rate is relatively high in the initial stage. With the increase in time, the difference between coal fractures and coal matrix blocks becomes lower and the gas diffusion rate decreases gradually. More >

Dengfeng Su¹, Yong Kang^1,2,*, Xiaochuan Wang², andan Zheng¹, DongyangLi¹, Binyuan Yan¹, Fuwen Yan¹

CMES-Computer Modeling in Engineering & Sciences, Vol.111, No.5, pp. 375-393, 2016, DOI:10.3970/cmes.2016.111.375

Abstract Tunnel though coal seam is one of the most difficult tunnels since its risk of coal and gas outburst and the complex geological conditions. According to the directional cutting of water jet and the characteristic of the coal seam and rock mass, this paper presents a new method of tunnelling though coal seam assisted by water jet slotting, which can be divided into improving permeability of coal seam and directional cracking in the rock mass. The mechanism of improving permeability of coal seam was stated, and the crack criterion of rock during blasting was established… More >

M. D. C. Magalhaes^1,2

CMES-Computer Modeling in Engineering & Sciences, Vol.105, No.6, pp. 441-465, 2015, DOI:10.3970/cmes.2015.105.441

Abstract The main goal of this study is to present an alternative and more efficient algorithm for a three-dimensional Component Mode Synthesis model to be used on sound transmission problems. The influence of fluid-structure interaction on airborne sound transmission problems is analysed using this model, which is based on simple volume geometries. In principle, the same procedure can also be applied when the component modes are obtained from alternative numerical techniques. The modal behaviour of acoustic volumes and a partition is implemented in two steps. The novelty of this alternative model is that the structural modes More >

Yiyu Lu¹, Chenpeng Song^1,2, Yunzhong Jia¹, Binwei Xia¹, Zhaolong Ge¹, Jiren Tang¹, Qian Li¹

CMES-Computer Modeling in Engineering & Sciences, Vol.105, No.1, pp. 69-86, 2015, DOI:10.3970/cmes.2015.105.069

Abstract In underground coal mines, hydrofracture can cause the increase of breathability in the fractured coal bed. When the hydrofracture crack propagates to the interface between the coal bed and the roof-floor stratum, the crack may enter roof-floor lithology, thus posing a limit on the scope of breathability increase and making it difficult to support the roof and floor board for subsequent coal mining. In this work, a two-dimensional model of coal rock bed that contains hydrofracture crack was constructed. Then an investigation that combines the fracture mechanics and the system of flow and solid in… More >

Wang Yang^1,2, Juanjuan Li¹, Jian Yang^1,3, Lin Wei⁴

CMES-Computer Modeling in Engineering & Sciences, Vol.104, No.6, pp. 471-491, 2015, DOI:10.3970/cmes.2015.104.471

Abstract Harvesting is the most difficult and costly operation in cassava production. Currently, most cassava harvest still depends on manual tools. Effective mechanized harvesters are necessary to improve harvesting quality and reduce production cost. Therefore, it is very important to figure out key information for designing an effective tuber lifting system used in bionic “dig-pull” harvesters. A numerical simulation model of human-stem-tuber-soil system was developed to carry out numerical simulation of manually pulling tuber. Coupling algorithm of Lagrange and smoothed particle hydrodynamics (SPH) was used in the model. Lifting mechanism of experienced farmer was studied at… More >

F.Z. Chen^1,2, H.F. Qiang¹, W.R. Gao¹

CMES-Computer Modeling in Engineering & Sciences, Vol.104, No.1, pp. 41-68, 2015, DOI:10.3970/cmes.2015.104.041

Abstract A coupled method describing gas-solid two-phase flow has been proposed to numerically study the bubble formation at a single orifice in gas-fluidized beds. Solid particles are traced with smoothed particle hydrodynamics, whereas gas phase is discretized by finite volume method. Drag force, gas pressure gradient, and volume fraction are used to couple the two methods. The effect of injection velocities, particle sizes, and particle densities on bubble growth is analyzed using the coupled method. The simulation results, obtained for two-dimensional geometries, include the shape and diameter size of a bubble as a function of time; More >

H. Y. Fang^1,2,3, J. Liu⁴, F. M. Wang^1,2

CMES-Computer Modeling in Engineering & Sciences, Vol.99, No.6, pp. 473-490, 2014, DOI:10.32604/cmes.2014.099.473

Abstract Construction of electromagnetic wave propagation model in layered pavement structure is a key step in back analysis of ground penetrating radar (GPR) echo signal. The precise integration method (PIM) is a highly accurate, efficient, and unconditionally stable algorithm for solving 1-order ordinary differential equations. It is quite suitable for dealing with problems of wave propagation in layered media. In this paper, forward simulation of GPR electromagnetic wave propagating in homogeneous layered pavement structure is developed by employing PIM. To verify the performance of the proposed algorithm, simulated GPR signal is compared with the measured one. More >

F. Mechighel^1,2,3, N. Armour⁴, S. Dost⁴, M. Kadja³

CMES-Computer Modeling in Engineering & Sciences, Vol.97, No.1, pp. 53-80, 2014, DOI:10.3970/cmes.2014.097.053

Abstract Numerical simulations were carried out to explain the behavior exhibited in experimental work on the dissolution process of silicon into a germanium melt. The experimental work utilized a material configuration similar to that used in the Liquid Phase Diffusion (LPD) and Melt-Replenishment Czochralski (Cz) growth systems. The experimental dissolution system was modeled by considering axisymmetric and three-dimensional (3-D) domains. In both cases, the governing equations, namely conservation of mass, momentum balance, energy balance, and solute transport balance, were solved using the Finite Element Method.
Measured concentration profiles and dissolution heights from the experiment samples showed that… More >