非均质煤层瓦斯渗流的SPH方法模拟研究

Simulation of gas seepage in heterogeneous coal seam by SPH method

应用光滑粒子流体动力学(smoothed particle hydrodynamics,SPH)方法对煤层瓦斯渗流进行模拟研究。针对非均质煤层瓦斯瞬态渗流问题,利用Fortran语言编制了变系数瓦斯渗流偏微分方程的求解程序,通过虚粒子法处理边界条件,构建了无网格性质的SPH瓦斯渗流模型。进行了不同原始瓦斯压力和透气性系数时常系数渗流方法下结果的误差分析,同时考虑透气性系数受矿山压力及Weibull分布影响的非均质煤层,分析了非均质煤层中瓦斯压力及涌出量的变化规律。模拟结果表明:应用SPH方法能很好的模拟煤层的瓦斯渗流;矿山压力影响以及透气性系数按Weibull分布赋值的非均质煤层都会导致瓦斯渗流的非线性。

Smooth Particle Hydrodynamics（SPH）method was employed to model gas seepage in coal seam. Focused onthe problem of transient seepage of gas in heterogeneous coal seam,a gridless SPH model was built by using Fortranprogram solving the variable coefficient partial differential equation of gas seepage,and through the virtual particlemethod dealing with boundary condition. The errors of constant coefficient seepage equation under different original gaspressures and permeability coefficients were analyzed. The change laws of gas pressure and gas emission quantity wereobtained in heterogeneous coal seam with different permeability coefficients because of mining pressure and Weibulldistribution. Simulation results show that the gas seepage in coal seam can be simulated efficiently by SPH method.The heterogeneous coal seam with different permeability coefficients because of mining pressure and Weibull distribu-tion will lead to the nonlinear flow of gas.