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Abstract Equivalent construction method in statistics of coal?s pore structure was discussed；and the spatial- temporal evolution process of fluid flow was simulated at pore scale. First of all，the porous media model of coal medium was constructed using modified quartet structure generation set(QSGS) algorithm which integrates the nonlinear and anisotropic characteristics of coal?s pore structure. And then，single-phase gas flow through pores was simulated using lattice Boltzmann method. Based on the numerical simulation results，the main influential factors and the evolution pattern of coal?s permeability before fluid flow achieve equilibrium state were analyzed. The analysis results show that：(1) Permeability in porous media is dominated by the channels connected by pores with large size，but the migration in the paths connected by small pore and micropore was concentration diffusion behavior；(2) In the same spatial distribution variability pattern，there is a power law relation between porosity and permeability，but the power rate coefficient increases with the decrease of spatial variability；(3) Permeability is reduced gradually over time in porous media and the time needed before the flow reaches its stable state meets negative correlation power rate relation with porosity.
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Received: 02 September 2011
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2013, Vol. 32 
