基于LBM方法的裂隙煤体内瓦斯抽放的模拟分析

基于格子玻尔兹曼方法(Lattice Boltzmann Method, LBM)建立了可模拟裂隙煤体内瓦斯抽放的二维动力学模型，对流场压力和流动速度的分布规律进行了模拟.模拟结果表明：抽放压力、钻孔位置对抽放效果有很大影响,抽放压力增大，瓦斯流动速度加快，瓦斯抽放率提高；但是当抽放压力达到某一值时，抽放率反而下降，这说明抽放压力存在一最佳值；改变钻孔的位置，在流场上、下侧偏心开孔时，抽放率低于在流场中心开孔，且流场中出现了涡流，流体在涡流处有较大的压力梯度.

Simulation of gas drainage in fissured coal based on Lattice Boltzmann Method

A dynamic model for simulation of two-dimensional gas drainage in fissured coal was constructed based on Lattice Boltzmann Method(LBM),a numerical program to simulate the distribution rule of gas pressure and velocity was developed,and the gas drainage ratio was calculated by statistical method.The simulation results demonstrate that the drainage pressure and the position of drainage pore have great impacts on the gas drainage: with the increment of drainage pressure,the pressure gradient of gas round drainage pore turns bigger,and the velocity of gas flow turns faster,the gas drainage ratio becomes higher.But,as the drainage pressure reaches a certain value,the drainage ratio becomes lower.It is shown that the drainage pressure exists a critical value.As the drainage pore is in flank position,the turbulence occurs,and the gas drainage ratio is lower than that in core position.With offset relative to core position increments,the effects become more obvious.It is shown that the drainage effect in core position is better than that in flank position.The simulation results based on LBM coincide well with the related conclusions of gas flow by other methods,but the simulation program is concise and the gas pressure can be calculated directly.