Propagation of shock waves in a porous medium saturated by a liquid with bubbles of a soluble gas

Abstract

The process of evolution and reflection of shock waves of moderate amplitude from a rigid boundary in a porous medium saturated by a liquid with bubbles of a soluble gas is studied experimentally. Experimental values of the amplitude and velocity of the reflected wave are compared with the calculated results obtained using mathematical models. The process of dis= solution of gas bubbles in the liquid behind the shock wave is studied.Based on numerical calculations of the process of collapse of a layer of cavitation bubbles near a solid wall, Kedrinskii [1] observed the appearance of a series of high-araplitude pressure pulses on the wall, which are caused by inertial effects of collective collapsing of the bubbles. A powerful secondary shock wave generated by the collapse of a single bubble in the liquid was observed in the experiments of [2,3] by optical methods. Shima and Fujiwara [4] studied the interference of the neighboring bubbles on their disintegration and generation of secondary shock waves. Amplification of shock waves in a liquid with vapor bubbles or with bubbles of a readily soluble gas was studied experimentally in [5][6][7][8][9]. The amplification was observed both in the incident wave and in the wave reflected from the rigid boundary.The evolution and structure of pressure perturbations in a suspension of a liquid with solid particles and gas bubbles and the reflection of perturbations from the rigid boundary was studied theoretically and experimentally in [10][11][12]. Shreiber [13] proposed a model of propagation of nonlinear acoustic waves in a three-phase mixture. Evolution equations were obtained, which explain some experimental data on wave dynamics in three-phase media. The effects of interphase interaction in multiphase disperse systems including phase transitions and chemical reactions were considered by Theofanous et al. [14] and Hanratty et al. [15]. The stability of interfaces in multiphase media and the dynamics of solid and gaseous inclusions were studied.The evolution and structure of weakly nonlinear pressure waves in porous media saturated by a liquid or by a liquid with gas bubbles were investigated in [16,17]. The existence of two types of longitudinal waves ("fast" and "slow" modes) caused by different compressibilities of the porous skeleton and saturating liquid was shown.In the present paper, we experimentally studied the evolution and reflection of shock waves of moderate strength from the rigid boundary in a porous medium saturated by a liquid with bubbles of a soluble gas. The experimental data axe compared with calculations performed using the models proposed by Lyakhov [18] and Nigmatulin [19]. The process of dissolution of gas bubbles in the liquid behind the shock wave is studied.The experiments were conducted in a "shock-tube" facility [9]. The test section was a vertical thickwalled steel tube with an inner diameter of 0.053 m and a length of 1 m, which was bounded by a solid wall from below. The test section was filled by a saturated porous medium. The porous med...