NEMD simulation for obstructed methane flow in mica pore

The nonequilibrium molecular dynamics method was adopted for simulating high-velocity obstructed flow of methane in nano-scale slit-pores. The simulation results show that flow over obstacle would create a following low-density field with pressure lower than that in non-obstructed slit-pore. Vortex and reverse flow were predicted which were consistence with the bulk flow. Oscillatory wave and cavitations phenomena were observed under high-acceleration, indicating the existence of critical acceleration for the wave and cavitations formation. Interfacial tension near the obstacle was larger than that of normal liquid-vapor interface and would increase with the increase of the acceleration or length of obstacle. The calculation of interfacial tension also shows that Rayleigh-Taylor criterion works well even when two phase of driven flow were of the same particle.