In this paper,the failure caused by HRAM loads which were generated by high-speed projectile penetration,and protection technology of the fluid-filled structure were explored.A bubble was preset on the projectile traj...In this paper,the failure caused by HRAM loads which were generated by high-speed projectile penetration,and protection technology of the fluid-filled structure were explored.A bubble was preset on the projectile trajectory in a fluid-filled structure.Based on the reflection and transmission phenomena of pressure waves at the gas-liquid interface and the compressibility characteristics of gases,a numerical analysis was conducted on the influence of preset bubble on projectile penetration and structural failure characteristics.The results indicate that the secondary water-entry impact phenomenon occurs when a preset bubble exists on the projectile trajectory,leading to the secondary water entry impact loads.The rarefaction waves reflected on the surface of the preset bubble cause the attenuation ratio of the initial impact pressure peak to reach 68.8%and the total specific impulse attenuation ratio to reach 48.6%.Furthermore,the larger the bubble,the faster the projectile,and the more obvious the attenuation effect.Moreover,due to the compressibility of the bubble,the global deformation attenuation ratio of the front and rear walls can reach over 80%.However,the larger the bubble size,the faster the projectile velocity,the smaller the local deformation attenuation effect of the rear wall,and the more severe the failure at the perforation of the rear wall.展开更多
The Hydrodynamic Ram(HRAM)effect occurs when a high kinetic energy projectile penetrates a fluid filled area,e.g.,a liquid filled tank.The projectile transfers its momentum and kinetic energy to the fluid,what causes ...The Hydrodynamic Ram(HRAM)effect occurs when a high kinetic energy projectile penetrates a fluid filled area,e.g.,a liquid filled tank.The projectile transfers its momentum and kinetic energy to the fluid,what causes a sudden,local pressure rise,further expanding as primary shock wave in the fluid and developing a cavity.It is possible that the entire tank ruptures due to the loads transferred through the fluid to its surrounding structure.In the past decades,additionally to experimental investigations,HRAM has been studied using various computational approaches particularly focusing on the description of the Fluid-Structure Interaction(FSI).This article reviews the published experimental,analytical and numerical results and delivers a chronological overview since the end of World War II.Furthermore,HRAM mitigation measures are highlighted,which have been developed with the experimental,analytical and numerical toolboxes matured over the past 80 years.展开更多
文摘In this paper,the failure caused by HRAM loads which were generated by high-speed projectile penetration,and protection technology of the fluid-filled structure were explored.A bubble was preset on the projectile trajectory in a fluid-filled structure.Based on the reflection and transmission phenomena of pressure waves at the gas-liquid interface and the compressibility characteristics of gases,a numerical analysis was conducted on the influence of preset bubble on projectile penetration and structural failure characteristics.The results indicate that the secondary water-entry impact phenomenon occurs when a preset bubble exists on the projectile trajectory,leading to the secondary water entry impact loads.The rarefaction waves reflected on the surface of the preset bubble cause the attenuation ratio of the initial impact pressure peak to reach 68.8%and the total specific impulse attenuation ratio to reach 48.6%.Furthermore,the larger the bubble,the faster the projectile,and the more obvious the attenuation effect.Moreover,due to the compressibility of the bubble,the global deformation attenuation ratio of the front and rear walls can reach over 80%.However,the larger the bubble size,the faster the projectile velocity,the smaller the local deformation attenuation effect of the rear wall,and the more severe the failure at the perforation of the rear wall.
文摘The Hydrodynamic Ram(HRAM)effect occurs when a high kinetic energy projectile penetrates a fluid filled area,e.g.,a liquid filled tank.The projectile transfers its momentum and kinetic energy to the fluid,what causes a sudden,local pressure rise,further expanding as primary shock wave in the fluid and developing a cavity.It is possible that the entire tank ruptures due to the loads transferred through the fluid to its surrounding structure.In the past decades,additionally to experimental investigations,HRAM has been studied using various computational approaches particularly focusing on the description of the Fluid-Structure Interaction(FSI).This article reviews the published experimental,analytical and numerical results and delivers a chronological overview since the end of World War II.Furthermore,HRAM mitigation measures are highlighted,which have been developed with the experimental,analytical and numerical toolboxes matured over the past 80 years.
