Numerical study on a bubble dynamic generated by ultrasound waves in liquid-saturated porous media
In this paper, the effect of increasing or decrea-sing energy transferred by ultrasound waves on the dy-namics of a cavitation vapor bubble in a confined space such as pores of a porous medium saturated liquid is in-vestigated. The main motivation of this investigation is identifying and understanding the mechanisms of the en-hanced oil recovery using ultrasound waves method in order to be able to recognize the limitations and important parameters in this method. Boundary element method for the numerical solution is used. The problem is solved for the cases with and without surface tension. Numerical re-sults show that by increasing the amount of energy trans-ferred to the liquid filled cavity, bubble growth and col-lapse rates shows a significant increase which results the acceleration of liquid particles around the vapor bubble at both ends of the cavity. As a result, the exerted force on the possible obstacles, like sand particles or trapped oil droplets, increases and moves them. Consequently the permeability of the porous medium increases. Increasing the permeability of oil well, leads to Enhanced Oil Recov-ery. The numerical results show that with increasing energy transferred to saturated liquid cavity, no significant changes occurs during the life time of the vapor bubble. The results also show that the effect of surface tension on the results, given the scale of the problem, is not signifi-cant.