行波驱动下空泡在可压缩流场中的运动特性研究

Cavitation bubble in compressible fluid subjected to traveling wave

基于波动方程给出了计及可压缩性的边界积分方程.以此为基础,求解行波驱动下非球状空泡的运动规律及其运动稳定性,并分析比较了行波频率、幅值以及初相位对空泡运动特性的影响.研究结果表明:较高的行波频率与较低的幅值是空泡稳定运动的充分条件.在一定幅值和频率的行波驱动下,空泡将在收缩阶段末期形成与行波传播方向相同的高速射流;计及流场可压缩性后,空泡脉动一次的时间减短,幅度减弱,射流顶点速度以及空泡内部压力的峰值随之减小;随着行波频率的增大或是幅值的降低,空泡脉动幅度与射流强度逐渐减弱;行波初相位的变化使空泡的初始运动状态随之改变,并影响非球状变形时的射流强度.

With the wave equation, the boundary integral equation with considering compressibility is deduced. Then the motion character- istics and stability of cavitation bubble driven by traveling wave are obtained. The influences of wave frequency, amplitude and initial phase on the motion of cavitation bubble are analyzed. The results show that the motion stability is enhanced with the increase of drive frequency or the reduction of drive amplitude. With appropriate frequency and amplitude, the jet will be formed at the anaphase of contraction, and the direction is the same as that of the traveling wave. With the consideration of compressibility, the time for once pulsation of the cavitation bubble is shortened and the pulsation amplitude is reduced, correspondingly the jet tip velocity and the inner pressure also decrease. With the increase of drive frequency or the reduction of drive amplitude, the pulsation amplitude and intensity of jet decrease. The variation of initial phase will lead to the changes of the initial motion state of cavitation bubble and the jet strength.