格子BOLTZMANN方法模拟泊肃叶流，周期和非平衡外推边界(The lattice BOLTZMANN method is used to simulate the flow and periodic and non-equilibrium extrapolation boundary of the flow)

利用周期性边界条件，计算二维单周期橡胶圆柱空腔的透声系数和吸声系数。入射界面为水，出射界面为空气。(Using periodic boundary conditions, the sound permeability coefficient and sound absorption coefficient of two dimensional single periodic rubber cylindrical cavity are calculated.)

周期性边界条件，边界条件，周期性，周期性边界条件；(periodic boundary condition)