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Abstract In order to obtain the real physical model to characterize the pores and fissures of coal mass and to numerically investigate the internal gas flow，the segmentation of DTM threshold was implemented to segment the CT images. The method of DTM threshold was amended by adding Wiener filter denoising. Its correctness was validated with the three-dimensional reconstruction. The abscissa value corresponding to the maximum value of the minimum on the porosity curve was found to be the optimal threshold. Numerical simulation of gas flow was conducted based on the real physical model of pores and fissures of coal extracted using the DTM threshold segmentation method. Simulation results showed that at the micro-scale(＜100 µm)，the gas flowing pores and fissures agreed with the high speed nonlinear percolation of Forchheimer. The flow velocity grew rapidly in fissures and changed randomly along the direction of flow. The permeability coefficient and non-Darcy coefficient were calculated according to the fitting parameters on average flow velocity.
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2016, Vol. 35 
