Ghost Fluid法を用いた気液二相流での圧力波の伝播に関する二次元直接数値計算

抄録

Direct numerical simulations are conducted for the propagation of pressure waves in a bubbly liquid by taking the compressibility of both gas and liquid phases into account. In the simulation, the interaction of multiple in-line bubbles with an incident shock wave in a channel is computed with the improved ghost fluid method. When the collapse time of each bubble (T_b) is nearly equal to the propagation time of the incident shock wave that passes through each bubble (T_s) (i.e., when the pressure amplitude of the incident shock wave is sufficiently high), the shock waves generated from the upstream collapsing bubbles affect strongly the motion of downstream bubbles. On the other hand, if T_s/T_b <<1, the pressure wave associated with the bubble oscillations propagates downstream after the incident shock wave passes through the bubbles. The propagation speeds for various void fractions obtained from the direct simulation are compared with those defined for isothermal homogeneous mixture. The results show that both agree with each other with less than 10 %.