On the non-equilibrium dynamics of cavitation around the underwater projectile in variable motion

9th International Symposium on Cavitation

Chen, Y.^1 ; Lu, C.J.^1 ; Li, J.^1 ; Chen, X.^1 ; Gong, Z.X.^1

School of Naval Architecture, Ocean and Civil Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai

200240, China^1

关键词: Damped oscillations;    Dynamic behaviors;    Equivalent radius;    Non-equilibrium dynamics;    Periodic oscillation;    Pressure disturbance;    Pressure oscillation;    Underwater projectile;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/656/1/012149/pdf
DOI  :  10.1088/1742-6596/656/1/012149

来源: IOP

【 摘 要 】

In this work, the dynamic behavior of the non-equilibrium cavitation occurring around the underwater projectiles navigating with variable speed was numerically and theoretically investigated. The cavity collapse induced by the decelerating motion of the projectiles can be classified into two types: periodic oscillation and damped oscillation. In each type the evolution of the total mass of vapor in cavity are found to have strict correlation with the pressure oscillation in far field. By defining the equivalent radius of cavity, we introduce the specific kinetic energy of collapse and demonstrate that its change-rate is in good agreement with the pressure disturbance. We numerically investigated the influence of angle of attack on the collapse effect. The result shows that when the projectile decelerates, an asymmetric-focusing effect of the pressure induced by collapse occurs on its pressure side. We analytically explained such asymmetric-focusing effect.