Numerical simulation for flux change in laminar flow under oscillating boundary condition with Lattice Boltzmann method

Since the amount of oil production in the world is decreasing recently, it is of importance to seek the technological development for enhanced oil recovery (EOR). Seismic stimulation is known as one of the methods for EOR. Numerous observations show that seismic stimulation could improve oil production and therefore is called as the seismic EOR. However, in order to use seismic EOR more efficiently, we need to understand the mechanisms in Eulerian specifications in flow analyses. In this study, we attempt to evaluate the flux change in viscous laminar flow under a boundary condition oscillating with various frequencies and amplitudes for modeling of interstitial flow. In this study, we use Lattice Boltzmann method (LBM) described by Boltzmann equation. We discuss the difference between the effect of wall oscillation and the pressure disturbance. Then we consider seven major characteristics which would have influences on the flux change: i.e. the amplitudes of wall oscillation, the frequencies, the incident angles, the aspect ratios of pore length to pore width, the thermal effect and interfacial tension. The pressure disturbance has little effect to improve flow and wall oscillation may have large effect to improve flow. In wall oscillation, all characteristics are possibly related with the amount of flux change, but have not been elucidated their mechanisms in detail. In our simulation, the flux of a single-phase flow could increase with large amplitude, high frequency, large angle of incident to the wall, large aspect ratio or large scale. Considering thermal effect, the flux could increase more then not considering that, because wall oscillation generates periodic velocity change and a little temperature increase. In this simulation, the flux of two phase flow could increase with large amplitude, low frequency. On the other hand, the vertically oscillating wall has smaller effect or flux reduction effect even if the other characteristics satisfy the condition to cause the flux increment in the case of horizontal oscillation. Considering flux change under single-phase flow and multi-phase, we found that seismic EOR has the possibility of flux change under the wide frequency range. Our numerical results imply that the flow resistance increases by the velocity difference between the wall and the center of flow. It is also suggested that the fluid extrusion is generated by partial pressure gradient near the wall, and the oscillating boundary may cause pressure loss. The purpose of this study The condition for this simulation