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Abstract A new dynamic model for simulation of gas flow in fissured coal is established based on lattice Boltzmann method(LBM)，and is used to simulate two-dimensional gas flow in fissured coal. The simulation results demonstrate that the mining differential pressure has a great impact on the flow velocity，the porosity pressure and the pressure gradient of gas in fissured coal. Under the condition of mining pressure，the flow pressure of gas in fissured coal fluctuates at the beginning of seepage，and the amplitude depends on the differential pressure between the two ends of flow field. Then the gas pressure becomes stable，and the system energy reaches its equilibrium state. At the moment just before gas pressure gets its peak value，the gradient of gas porosity pressure becomes very high，and it is the primary reason for coal outburst. Along with the increment of mining differential pressure，the gas flow in fissured coal turns from laminar flow to turbulent flow gradually. As mining differential pressure is very high，the gas pressure appears divergence，and the dependence between mining differential pressure and gas pressure evidently becomes nonlinear. The velocity of gas flow becomes faster along with the increment of mining differential pressure，and the velocity in the middle of the flow field is faster than that on the sides. The results based on LBM coincide with the related conclusions of gas seepage by other methods very well，which indicates that LBM is an effective method to simulate gas flow in fissured coal. LBM provides a new method in further studying of coupling theory between coal and gas，and outburst mechanism of gas in fissured coal.
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Received: 14 April 2007
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